Are there any tricks or pitfalls in timing gear changes?
3 basic tips 


Try to be predictive in your shifting. Don't wait until you really need the next lower gear to change gears. Try to do it before your cadence drops to where you're mashing on the pedals
Ease up on the pedals when shifting. If you missed on the first tip, then let up on the mashing very briefly during the downshift. This will aid the chain in transitioning from one cog/chainring to the next. With some practice you can even get the timing right to where the chain will climb (or fall) during the least powerful part of your pedal stroke (6oclock/12oclock-ish) during sprint (or just normal) pedaling
Don't shift the front and the back at the same time. Try to drop the front chainring first and stagger upshifting in the back by a split second. This will help reduce drivetrain issues like dropping your chain and chainsuck.