Any good tips for playing as Trapper?

Watch otzdarva. That's all you need to hear

Here's a tip that works well for me often enough. Don't break pallets! After one is thrown, trap one side of it (especially if it's grassy). This pallet will feel like a safe haven to other survivors in future chases, as well as break the loop of the current chase if they watch you trap it. I've had a single one of these traps catch all 4 survivors in the past!

The best tip is don't play trapper. Play hag instead. She is similar to trapper but almost strictly better in every way except her move speed.

Otz has a good trapper video or two. Entitylefthand and Humerogamers are pretty good trapper mains on twitch.

Always trap the major building in the map. Always. Even if the traps are obvious. It's better to lay multiple traps around the building than just one, to make the survivor think they took care of the trap there, when in fact there are more waiting around. Every survivor will eventually run there knowing it's a powerful loop area and find themselves trapped in chase.

At the Institute you need to change your mindset a bit. It's no longer about hiding traps, because they'll be visible. On this map it's more about closing down loops and passages. When they realize a door or window is blocked by a trap, their choices become limited and you can catch them more easily. If they don't notice - SNAP! So go for nice bright "detour" signs to force their path.

If you DO want to try to hide a couple traps, I've found that putting them right on the transition of a doorframe can help camouflage them a bit. There are a few grassy spots, but those are often anticipated. And as was mentioned earlier, staircases pay dividends. Trap the very top step. Any further out and they can dodge around it once they realize what they're looking at.

i'd say one of the biggest things a Trapper needs to learn is how to optimize his trap usage.

in general, there are two types of traps you can lay out:

1) the Catchers

2) the Deniers

a "catcher" is a trap you place around loops that is supposed to catch survivors who try to loop you off guard. those are the main traps you will want to be placing, as they will be the ones that wont get found and disarmed ASAP. you need a decent looping knowledge for them to be effective though, as you will have to predict the survivors path and then trap it. this trap will also not work when a survivor just holds W and throws down every pallet in existance, but sometimes you can force them to loop a certain area you trapped previously. you can also place "catchers" on routes that are not even at loops, but you expect survivors to run through when trying to get to something specific, such as a loop or a hook. you always want to hide these traps within the environment though - tall grass, objects they can partially clip into or hidden around a corner where survivors dont expect it (best shot at using these on indoor maps, yet still ineffective)

a "denier" is a trap you place to deny the usage of a certain window / pallet. these traps are placed right in front of the pallet / window and are extremely obvious to survivors - they are not ment to catch a survivor, all they have to do is to stop them from using this specific pallet or window. you should usually only really place them at god pallets though, as these are a pain to loop around and you want to lure survivors away from them and into the other, prepared tiles. one important thing to note here is, that you never want to place it directly in front of the window or directly inside the pallet! you always want to place them in front of the pallet, so that the survivors cant just drop the pallet and vault over the trap and you always want to leave a small area between your trap and the window, as survivors could otherwise fastvault the window from the other side, jumping over the trap without being caught.

you need to find a good balance between those two trap types. since you only have 6 Traps by default, i would suggest placing one denier at the shack pallet and 4 catchers around the area you want to defend.

you should also always leave one of the Traps in your hand, as that is a very strong loop denial tool. if you end up at a loop you havent trapped and dont want to run around, trap the pallet right in front of their eyes. they are now forced to leave the area and potentially end up in one you prepared earlier.

you will also need to get creative with your trap placements. if your catchers are placed in well known spots, they will be disarmed by survivors rather quickly - you should also not just reset the same catchers over and over when they catch someone, as that will lead to the same outcome. always move them around so the survivors never know when they are about to step into a trap or not.

also, be aware of SWFs, Small Game (or any other trap / killer reveal perk) or Maps. if you suspect the survivors to be in a SWF, you can not trap hooks anymore, as the traps will get called out immediately and then disarmed. if you see someone with a map, you also need to be aware that they might be able to track your traps and reveal them to themselves and, in case of a certain Add On / SWF, to everyone else aswell.

the best thing you can do here is to get rid of the survivor who keeps disarming your setup asap.

in indoor maps specifically you are basically screwed.

all you can really do is to place deniers, which will only benefit you when the survivors dont spend some time checking their looping locations for potential traps / when the map doesnt come with a huge amount of pallets to begin with (hello, Hawkins).