Assuming you already have traditional bushwalking gear and are looking at lightening your load and enjoying the freedom of Ultralight (UL) backpacking. Here are some rules and advice about going UL that I have learnt (sometimes first hand) over the last 6 years:
Keep your old gear. You don’t become UL overnight, it’s an evolution, a transition, a learning curve. Plus if a family member or friend decide they want to come for an overnighter, you have gear to lend them. There are other reasons as well, so keep that old gear, at least to start with.
Buy your UL pack last. No point buying a UL pack if you can’t get all your gear into it and no point buying a pack that after a year, is too big and you want a smaller pack. That's not totally true because in winter or on longer walks, you may need a bigger pack, but hold off on buying a pack for a while, at least until your old pack is looking half empty.
Create a spreadsheet. Buy some cheap scales off ebay and list every bit of gear and the weight of each item. The reason you do this is to justify buying equipment. A general rule to get started is NOT to buy anything that isn’t saving you at least 1 gram per dollar spent. So lets say I can afford to buy a Quilt for $600 which reduces my overall weight by 700g. Or I can buy a Tent for $600 and save 1400g. I’m going to buy the Tent first because I get a bigger weight saving for my dollar. Eventually you will reach a stage where you can’t buy anything for $1/g or less and at that stage, you will almost certainly be UL.
There are websites like [url]geargrams.com[/url] that you can use. Personally I use Google Spreadsheets, you could also use Excel and that way, you can copy and paste your gear list into a new tab, cull the gear you don’t want to take and have a pack list for your walk.
Don’t pack your fears, learn to adapt. Most people carry a whole lot of crap they don't need. The general rule is to go for a “shakedown”, an overnight walk and anything you didn’t use, throw away. But it’s a lot more than just that. Do you really need a knife, fork and spoon when you can get away with just a spork. Do you really need a cup, plate, bowl, pot and frypan when you only need a cup to drink, eat and cook in? Do you even need a pillow when you can stuff your puffer jacket in your pack to use as a pillow? These are the type of questions you need to ask yourself and try out. It’s important to stay safe, dry and warm and you don’t have to sacrifice any of that to shed weight, but you will need to change some of your ideas on what you actually need.
Do your research and buy once. If you’re a compulsive buyer, don’t. Researching all the different products out there is one of my favourite past times, searching all the different cottage industry websites, getting excited about going for a walk with my new gear and lightening my load. But it’s easy to buy something and regret not having bought something else later. So do your research and once you’re ready to pull the trigger, hold off and give yourself a few days or even better, a week before buying. Don’t be in a hurry, the gear you already have is perfectly fine.
Be happy to evolve. Did I just say buy once, well that's true but if you buy right, you will still end up with 2 of most things. Don’t try and be Super Ultralight straight up. To give a few examples, the first UL tent I bought was a Tarptent Protrail (770g), still got it, still use it. If I’m not sure about the conditions or it looks like a lot of rain, I'll take the Protrail. Most of the time, I travel with a DCF (Dyneema) tarp, bugnet and Polycro groundsheet (~400g all up). Starting off with the Tarp setup wouldn’t have been a good idea. I probably wouldn’t have liked Tarping to begin with and may have given up on the idea of going UL.
I’ve got maybe a few to many packs but I started with an Osprey Exos 50L and then, when it became too big for overnight walks, I bought a Wilderness Threadworks Sonder 36L, which is lighter, more durable and my pack weight is so light now, I don’t need a hip strap. But the Sonder isn’t big enough for longer walks so I still use the Osprey.
What I’m saying is that as you evolve, so does your gear but if you bought sensibly first up, that gear you first bought, will still be useful and still get used.
Don’t get sucked in by marketing hype. Most reputable companies like Sea to Summit make claims that are accurate, others don’t, even some of the big names. Waterproof boots that aren’t waterproof, Rain jackets that don’t keep out the rain… do your homework, read the reviews.
Beware, it’s addictive. Some people take UL to extremes. Cutting off the labels, Titanium Shepard Hook stakes, high-energy light-weight foods etc, are all good ideas to know about and try but don’t go as light as possible and sacrifice comfort or safety. Don’t get a Quilt that is too small. Not sure, get the next size up. Don’t buy a cheap chinese UL tent if you’re over 5’ 8’’, you probably won't fit. Don’t get a CCF mat or a small inflatable mat if it means you’re getting a bad night's sleep. Don’t buy a 450ml cup to cook with if you’re a big eater and can’t comfortably fit your dinner in it...
There’s Super UL (SUL) and Stupid UL. In general, if in doubt, get the next size up. Ultralighters refer to this as “good weight”.
Where to buy all this gear. Typically most of it is sold direct by what are called “cottage” manufacturers. Not all are small and there are a lot of them, I don’t want to list them all here. You need to do your research but to get started, try https://www.99boulders.com/ultralight-backpacking-gear-vendors
There are major companies that also provide UL gear to retailers. Some of the better known are Sea to Summit, Nemo, Osprey, Thermarest, Big Agnes among others. You tend to pay a premium for their products as the retailer needs to make a dollar as well. On the good side, you can walk into a shop like Paddy’s, have a look feel and see if they’re right for you. Definitely clothing and shoes, I always try before I buy which limits your options as not all the good stuff is available here.
Get out there. But don’t start with a 1 week odyssey of the Tasmanian Wilderness. Start with an overnighter, then a long-weekend, work your way into it because there’s a learning curve in all of this. Most are easy learning curves but you still need to learn them first. Better to abandon with a 4 hour walk to civilization than watching your new UL tent blow away in a gail, 2 days walk from anywhere! Oh and take a Personal Location Beacon (PLB), at 150g, it’s good weight that can save your life.
Some good resources I’ve found along the way:
https://www.adventurealan.com Alan's site has been invaluable to me over the years. I don't follow his brand recommendations per se but his advice and philosophy behind UL hiking is second to none IMO.
http://bushwalk.com The best resource for Australian Bushwalking. A lot of amazingly experienced and knowledgeable people contribute to this site. Info on walks, gear, safety... and a market place with lots of UL gear for sale. The best, well priced UL gear gets snapped up quickly, so know what you want and be quick
https://www.theultralighthiker.com Steve is a little out there but he comes up with some fun, novel ideas. Some of them are quite brilliant.
https://www.thehikinglife.com Cam Honan is another blog site I like.
Also check out youtube, there’s a lot of rubbish on there but some great vlogs and gear reviews amongst it all.
Anyway, I hope that helps and I’m sure your adventure into Ultralight backpacking will be a rewarding one, well mostly, things don’t always go to plan. Did I tell you about the time I fell in a creek...