Wireless RGB led controller circuit with motion sensing - design feedback
Just a few quick comments (past sleep time). 

Fatten pads as much as possible.
J1 (and many other) pads can be oval and thicker to avoid loss of pad during etching, drilling and soldering. 

Anything with mechanical attachment wants all the copper anchor you can reasonably give it. 

Track between pins on ?pot? at lower left is OK but you could run track from pin 1 out and up and track to pin 2 around the end and have fatter pads and tracks. 

Q1 2 3 stand vertical ?
OK if on heat sink with mechanical support for FETs.
If not heatsunk then 'lying down' gives MUCH longer life. 

R4 5 6 slightly staggered ? - only cosmetic but proper alignment improves looks. 

Gate drive R's help damp ringing. - a few Ohms usually.
IF switch speed is high you may need gate drivers -
OK if &lt;= 1 kHz and MAYBE &lt;= 10 kHz. 

Power supply can be &lt; 12V - add a LARGE filter capacitor.
ENSURE it is not > 12V - some clone nanos do not like over 12V. 
Lower reduces on-device regulator dissipation. 

More can be said .