Choose a day that is partly or mostly cloudy, and preferably when the cloud cover is thin and spread out. Thin clouds can't hide general aviation aircraft as easily. Minimize your time beside the clouds, and inside any opening you choose to go through. Get above the clouds quickly, stay there as long as is safe, and then get back down below quickly. Try this adventure only in a remote area away from busy air traffic.
Airplanes ascending or descending through the clouds are a real danger.
Use a GPS to monitor your ground speed as upper level winds can be surprisingly strong. I found myself actually drifting backwards a time or two. Stay close to your takeoff point, in case you do drift or get disoriented. Note also, that the air temperature drops an average of about four degrees per thousand feet as you climb. Review FAR103 as it pertains to flying near clouds, and with respect to the requirement that you navigate only with respect to the ground.