i see most demos surf the rocket to get away and pipe/sticky from afar

You should always be with your team and have someone (not medic) between yourself and the enemy.
That's a good way to start.

3 options vs soldier:
1. Don't be there.
2. Get out of there.
3. Be next to a scout and watch the soldier die.

Thank you for your contribution

as someone that has played medic for some time, I try to apply some basic positioning principles (with some exceptions) to when I'm playing demo

• Try to keep at least one teammate in front of you, or at the very least in close vicinity
  
• surf damage whenever you can
  
• don't +forward like an idiot because scouts will +forward you harder and you will just end up feeling bad and frustrated and looking at a respawn timer

the last one is a bit subjective but when I was cleaning out demos on my hard drive I was cringing so hard at how bad I used to be at +forwarding when I shouldn't have

as far as developing better positioning, watch over your own demos and gameplay. Question every single death and ask yourself if you could have possibly survived

also to answer your bonus question, sometimes prefiring a sticky to potentially knock a soldier off his intended course can really help if you know he's going to be bombing you. The better answer is as setsul mentioned, stick with a scout so the soldier will essentially have to fight 2 people instead of one. That being said, going for the airshot isn't half bad, but if you're spending your entire clip of grenades trying to hit the airshot it's probably better if you save them when scouts try to get in your face

try not to be dead when your medic is dead

Time travel back to before 2014

Since Demoman's nerf you basically have to prioritize staying alive more than previous iterations of Demoman in the meta. Never be at the front to initiate fights or try to take fights 1v1 since the class turned into a big squishy babbu. Only play midrange if it's not a huge risk you'll die and if team is around you or if you have someone with you (most of the time).

Charge stickies and save as many as possible for when the enemy is in the "get pooed on" situation. (i.e. trying to come in/back out through a shitty enclosed choke point).

alright here goes nothing

if you feel like ur not being effective on demoman, theres a couple things you should look into but first and foremost, demoman is a class that is best suited for high DPS/DMG and area denial, you will generally never top frag and will place 1st to 4th on the highest damage in server, given if you are playing well (<--- these are my standards for myself), it is very important to understand you dont have to do a whole lot to be effective on demo, everything (especially post-nerf demo) is based off positioning and timings, and of course DM

if you're getting caught out, its because you are overextending (+w into four players), or you are not pre-emtively reading a situation (i.e my med dropped, what do now) and adjusting your positioning / decision making based off that, thats called reactive playstyle, you need this for every situation both in game and in actual life as well, only experience and demo reviews will help you understand how to position yourself and deal a great amount of damage while being able to survive

another thing is, you will need to stick with someone on your team always, never be alone unless you are self sustaining and baiting yourself (i.e I Am Scout I See Demo Alone In Main I Rush Now), next thing you know the kills are coming to you rather than you trying to get kills

you should never die to a unexpected soldier bomb, thats why your scout buddy is there to kill him, however you as a player (this goes for every class) need to keep track of everyone, including soldiers, so then you dont die and be like where he come from?

aside from all these tips the only thing that will make you better is matches > scrims > pugs
good luck

quickie bombs make everything easier since you can do 164 with a fully charged sticky

Demo didn't actually get much weaker in 1v1s due to the nerf... Stickies that hit the ground before detting have full, instant, pre-nerf damage radius. With a scout +forwarding you your stickies are going to be ground stickies, not air dets. The nerf primarily weakened the ability to do mid range and long range damage.

What yewl said ^^

Tbh I really didn't notice that much of a difference at all after the demo nerf. I'd argue the only real major difference is kritz effectiveness.

On topic though, learn how to surf damage effectively. Being able to surf any damage (especially meatshots) is possibly one of the most important skills a demoman needs to have.

how would you recommend practicing surfing damage? surf maps?

ammomod

I've never really practiced surfing directly tbh. The only real tip is to make sure you jump just before the damage is inflicted upon you at which point you can airstrafe the damage in whatever direction you like.

surf maps are lame for practicing surfing tbh because it doesn't teach you speed limitations for air strafing. the faster you are the less rotational speed u can manage without "snaping" your strafe

jump maps and MYGAMINGEDGE are better

To practice surfing outside of scrims/matches, I would recommend lots of DM servers. There will never be a shortage of scouts rushing a demo in DM servers so you can get lots of experience timing your jumps to surf the damage.

or an alternative to playing demo in DM/MGE could be to play medic, where surfing is incredibly essential

it's also good to be well rounded as a player and be able to play more than one class/role at a competent level

I'd really recommend trying quickiebombs, especially if you are good at hitting pipes

Use the iron bobmber if you aren't already. You will instantly become better.

This is incorrect. Stickies on the ground will now have full radius yes, but that radius will be the same as rocket radius. Pre nerf radius was something like 20 percent larger than rocket radius.

That's the problem i have too. I know where to go to stay alive, but then i'm quite far away from the fighting and all I can do is 40 damage sticks or hope someone dumb makes a mistake I can punish, plus I don't really take any pressure away from my team.
The moment I try to go closer or go on the offensive I get focused and die.

Also I have trouble finding good damage on process/reckoner/snakewater. I can deny crates/high ground no problem, but actual non dumb players do not go within my reach and I feel like i'm left without targets in sight. And all of the sudden 3 players show up from blind spots and get me. Any tips?

Pre nerf radius was 10 feet, now it's 9.1 feet, same as rockets. At least pretend to aim before you complain.
Properly aimed stickies and stickies on the ground will still do a lot of damage if you actually hit them and not just det them in the general vicinity.