If it's a hard stick like the green oxide or red rouge, rub it on fast like a crayon, you want the friction to melt the wax that binds it a little. If it's a paste, just rub it on.
To find the angle, put the blade down flat against the strop and push edge forward but with no down pressure. Bring the spine of the blade up until you feel the edge start to catch on the leather, don't push hard or you will cut the leather. Mentally remember this angle while stropping. To strop, pull or push the blade spine forward this time with very little down pressure while keeping the blade at that angle from the first step.
This may not be the only way to do it, but i find it works well with my f1 and other knives.