I live at sea level as well and am training for 14ers. I am limited on my time when I do get out to hills, so I do not have the time for acclimatization. The best I can do is just build up my aerobic base as much as possible, stay very well hydrated and go fast and light on my climb. I usually start trying to hydrate well at least a day or two before my climb. It can be difficult to want to drink once you’re up there, but I found it really helps me. As far as I know, altitude training masks don’t work.
I also feel that focusing on aerobic work at nose breathing pace has given me the best results, versus focusing on sprints. Though, I do incorporate hill sprints into my base period for strength training.
I have a post about this in the mountaineering section and Scott gives some useful information about strategy and what not.