Mods keep crashing my minecraft?

So I deleted everything I'm suppose to. The META file please don't say anything about it… Cause that is already done… I currently have the mod Mo Creatures mod and Plenty of bioms mod… They work fine… But if I put something else in there it crashes. SOME work, very few… But I will get a mod a lot of people use but it still crashes and sometimes it doesn't crash my minecraft, it will be in the mod folder but not actually show up on minecraft… I doubt its the mods cause people use them… Please let me know how to fix this… And please only comment if you have an solution.

I have had the same problem many times before. 1st of all, i use Skydaz mostly because the download is easy, and they have all the latest mods. 2nd, if it keeps crashing, consider deleting minecraft completely and re-installing it. If you have worlds that you don't wanna lose, i'm not sure. I have always just played with mods. Let me know if this helps.

It is more likely that your mods are clashing with each other. Some mods are not compatible with other mods and Forge and some only work with forge installed. Make sure you read the compatibility list before installing mods.