ctietze, 
Best things I discovered w.r.t. keyboard customizations:
Home row modifiers; long-press "F" for shift, for example. Works really well when writing!
Space cadet shift keys; hold shift for shift as usual, but hit the left key for an opening, the right key for a closing parens: ( )
Yes it's kind of stupid to have one key become 'more shifty' and another 'less shifty' but it all makes sense, trust me