Get a spray bottle with just a little bit of dish soap in the water, that's the key. The soap keeps the caulk from sticking to everything and lets you slide the spoon right over it without pulling it up. I also dip the spoon in the soapy water between passes, makes a huge difference. You gotta work fast though cause once the caulk starts to skin over it'll get all lumpy and messy. Another thing I learned the hard way is to tape off both sides of the joint with blue tape first, then pull the tape off right after you smooth it. Gives you those perfect straight lines every time.