If you want to be lazy use VNAV. If your high on profile speed intervent and increase speed sensibly. If your in amongst the balls on a procedure(not approach) use the speedbrake, again sensibly.
Level change roughly 3 miles per 1000ft. If you stick as close enough to that "rule of thumb" and try and be as ahead of the aircraft as you can it makes life an awful lot easier.
I think the most important thing is if you see that you need to do something, do it early. Don't
around waiting to be hot and high and then decide to act.