Here is a good way. Somebody already said it, but I will say it again. Think of the new key. Think of the fifth note in the scale of the new key. Then play that chord, only with a seventh added. Bring out the dissonance a bit. When you move to the new key, you are "home."

For example, to move to the key of D, play an A7 for a while, then go to D. This works well for keys which are related.