On the series 2 it's not an issue at all.

I believe David Smith, the developer of Sleep++, said that on the original Apple Watch he wore it all day and all night and simply charged it in the morning and in the evening while taking a shower or doing the dishes or something like that. It doesn't take that long to charge the thing up all the way, so two short charges while you're doing other things would be enough to top it off.

On the series 2 the battery life is so good that just charging it while you take a shower in the morning is probably more than enough.

With gen 2 Apple Watch that shouldn't be necessary - I wear mine diligently and interact with it frequently yet the battery never gets below 70% at the end of the day, often only getting down to 90%, and the charge time is quite rapid. Stick it on the charger when going for a shower or some other short routine and you should have it back to fully charged when you're done.

Get the Milanese Loop band and it'll be even less of a pain because you can quickly put the watch on and take it off because it's magnetic. A lot easier than a buckle or pin fastener.

For anyone interested the sleep tracking app I use, Sleep Watch, automatically figures out when you're sleeping and awake so you don't have to manually initiate the app. I guess it interprets movement data from the accelerometer and can tell the difference between slight movements in a sleeping state and respite during wakeful periods.