You can write your topic however you want, but you need to answer these questions:
What do you want to achieve? Keep it simple and clear!
I want many trees without having a significant performance impact
What is the issue? Include enough details if possible!
Having lots of trees are causing some lag to my game
What solutions have you thought of so far?
I converted trees to Meshparts but there’s still a little lag
After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!
I suggest setting all MeshPart RenderFidelities to Performance if possible. Should reduce lag on laggy devices. Also disable CanTouch, CanCollide, and CanQuery on all leaf MeshParts.
Can you provide some examples of trees you’ve been using?
If you’re using entirely 3D trees perhaps the poly-count is too high, this is why a lot of roblox games go for low-poly assets when dealing with forests.
If your going the 2D textures route, you’ll have to get creative on how to balance performance and quality. For example, if your using a full 1024x1024 image as a leaf texture then duplicating it a bunch of times to place on every branch you’ll quickly run into a performance wall once you try to duplicate that tree hundreds of times. You can consider lowering the resolution of the texture, reducing the amount of textures used, or reducing the poly-count of the plane your putting it on, as that can also be taxing as its expanded out to a forest-scale.