How to keep Frame Rate up to 60 or more?

Does anybody know a very handy and easy way to fix The Frame Rate? Just that When I put to much content in the Map the Frame Rate drops badly. I put a block wall near the ends of the map to see if that helps and it seems it does but when I come to start building stuff that the player can walk around the frame rate drops all the way down to 20 so now I am hoping somebody out there has the answer I need just that How can we make AAA Games if the frame rate is going to keep on dropping?

Sry but I dont want to list every possible way to optimize. I kindly ask you do some research on your own since its a big topic with countless ways to optimize Performance.

https://www.google.de/search?q=ue4+optimisation

Profiling tools to find the Bottleneck:

If you know what causes the drop we can help you out. Otherwise we have to guess the right Answer for you. My guess would be your Assets themself are to expensive (Highpoly, many materials).