I let my chain slowly go slack and every week or so I reset the wheel - I don't bother with tugs as this weekly check forces me to tune up/check out the drive chain.
^ this. Plus stick an old tennis ball between the wheel and the seat tube. Roll the wheel to trap the ball and give you some good tension, but not too tight as stated here.
^ this. Plus stick an old tennis ball between the wheel and the seat tube. Roll the wheel to trap the ball and give you some good tension, but not too tight as stated here.