I love being able to change clothing or looks in SL in less than a minute on the fly. That is what outfits can do for you.
To create an outfit, wear the clothing, hair, skin, tattoos, shoes and any other accessories you would like to save as a part of the outfit. Next go to your APPEARANCE window, click on SAVE AS at the bottom of the outfits tab, name the outfit in a way that makes sense for you.
Now you can go to APPEARANCE and then the OUTFITS tab and right click on any outfit you have saved previously to change into it.
NOTE: NEVER Delete the objects you used to create an outfit, outfits are merely a collection of shortcuts to the original items in your inventory.