Just avoid cloudbase - that's were the folks with no engines hang out.
Seriously though - if it's a good (for gliders) weekend with a few nice Cu spread across the sky be prepared to find upwards of a dozen gliders circling under each one.
If there are "streets" of clouds be ready to meet a glider doing 80kts, in a straight line, at cloudbase.
Begin so aerodynamic they can be a little difficult to spot. Imagine this one a mile away!!!
OC619