You have to look down at your charts / approach plates some time, there's no two ways about it until GA comes with a Heads-up display....
An easy trick for working out heading to steer is to [shock....horror
] put the GPS on CoG, and compare it to my current heading. If the GPS displays a CoG of 300° and I'm steering 290° then I know there is a 10ish° drift to the right. If I actually want to go 290° over the ground then I have to adjust a bit to the left, until CoG=290°. Not forgetting of course that GPS is TRUE heading, and the DI is MAG heading,unless you can enter the Variation in the GPS.
For pre-flight stuff, I enter the wind velocity into my Casio flight computer and it tells me the course to steer
Cheers
EA