Learn how to do these jumps here:
Rocket jump as Soldier
Detonator jump as Pyro
Scorch Shot jump as Pyro
Grenade jump as Demoman
Sticky jump as Demoman
Sentry jump as Engineer

Uncommon types of jumps:
Overload jump as Soldier
Reflect rocket jump as Pyro
Flare jump as Pyro
Loose Cannon jump as Demoman
Trimping as Demoman
Energy orb jump as Engineer

What are these for? - You might ask.
Ambushing, hiding, escape routes, shortcuts, advanced Engineer nest spots, Sniper spots.

Not all of the maps are listed and definitely not all of the spots are shown.
These spots were manually found by me (trial and error) and there are rare cases where I actually searched map spots via Google. Completely useless spots (e.g. outside the map) will NOT be shown. If you find a new spot or you know one that wasn't mentioned, feel free to comment about it. I won't add it though as I consider this guide done.

If you can stand on one thing, objects alike that thing will work the same almost everytime.
This is mostly true with trees, since they always have hiding spots. This is true with other objects as well, for example on KOTH King, you can stand on 90% of the large signs. That's why I've only shown one example and not more.

Some things are obvious for others, while some things are completely new to some players.
Respect that. Plus if you are a competitive player, you might not know all spots on all maps. You never know what you may find here (even through I only went through the casual map pool)

Some spots are more useful than others.
There are places suitable for entire flanking strategies, while some spots are easily noticeable and they just there because why not.

There is a 2 megabyte limit on gif size.
This is why some gifs might look a bit wonky, it's difficult to maintain quality while also keeping the file size under control. Sorry :(

I forgot to add all of them. Oh well... One spot I remember that's super useful is in the tunnel between the Sniper spot and the stairs. It's on a small wooden ledge. If you know where that is, good for you.