on the standard bridges, the screw do i just keep them a little loose? I dont have a trem bar yet.

+1 on the "locking" method. I feed the string through the hole in the post, and kink it around. Then I wind a complete wrap with the loose end of the string passing under the "strung" part. Then I kink the loose end so it points more or less upwards, and finish winding the string so that it wraps itself down towards the base of the peg. Seems to hold tuning -- particularly on my Bigsby-equipped Gretsch -- better than the "standard" method.