Here is a great tool for you to use if you're unsure of what keys are complimentary with eachother. This simple chart is referred to as the "Camelot Wheel".

The Camelot Wheel is very simple to use. You can step from one key into the next either clockwise or anti clockwise, and between inner and outer circles. The only stipulation is that you can only move one step in any direction to stay in complimentary key with your current selection.  For example 1b will mix with itself (1b) or it will go with 2b, 12b and 1a.

If you jump to 12B (EMajor), from there you could either revert back to 1B, or you could switch to 11B or 12A. 

If you jumped from 1B to 11B, you would be jumping to a non-complimentary key, because it's more than one step away.

This is a simple and great method if you are no too familiar with music theory or dont know what keys will work together in your productions.You could also use this for building chords for example.