Here are some of the options that have worked for me and others here on the forum:
1. For AMD GPU users disable Catalyst from loading at bootup via MSCONFIG. This was a solution posted on the AMD forums and seems to help some people.
2. Disable origin in game as it's causes lag problems. To turn off Origin in game log into Origin, in the upper left hand corner click on the word "Origin" in the menu, and then click on "Application Settings". Next go to the "Origin in game" tab and uncheck the "enable Origin in game" box.
3. If you have the Raptr game tracking program running kill the process before playing BF4, this solved my randome FPS drops even on Dragon's Teeth maps.
4. If you are using MSI afterburning turn it off as some users report that it isn't playing well with BF4.
5. For Win8 users try running BF4 in Win7 compatibility mode. Right click on bf4.exe, select "Properties", then "Compatibility" and then choose run as Win7.