Need help- How to go around with creating trees for unreal engine 4

So as the title suggests, I could use hand, tips and tricks, and overall best methods for making trees, and then rendering them inside unreal engine 4. Here on top theres a tree created inside treeit, imported into unreal engine 4. Trunk material is custom/modified megascans material, leaves material is created by me (texture was one of the provided).
As you can see, it doesn't look very impressive... looks hurrendous in fact. 


Heres a shot in the scene I want to use it (and after creating few other trees, use them as a forest in this little level I am working on). This is pretty much my first time making so many assets by myself, all models here are made by myself (megascans materials though, I hope thats considered as okay or acceptable). However, trees (or overall foliage) is a huge unknown to me. Thats why I need a help, how can I make trees look good?



Shot from treeit

So, since I don't wanna pay/pirate speed tree, I decided to use treeit (instead of modeling it by hand in blender which would only take more time, effort, and give off worse results). Every time I create a tree, that I have no clue how to improve on, it always looks odd (proportions maybe?). Looking at references or examples from other games don't really help me much, since I can't tell what exactly is wrong (apart from leaves). 

So, if anyone experienced could really help me out (since I am a novice in creating game foliage) that would help me greatly. The level am working on now is the first one where I made nearly everything (except textures) myself instead of using assets provided to me, and I want to learn and make it the best I can. If its a wrong board, please excuse me since I am not really experienced around here. Hope to get better at that too. Thank you, and have a nice day!