Get someone else to give you a route on a simple old fashioned bread crumb trail GPS. Follow it till you come to the end and then, switch it off and then find out where you are with map and compass and proceed to another destination.
Also walking at night with map and compass alone will start to make you appreciate the minor details on a map. Walking in a full moon will put a completely different "light" on a mixed route of cross country and lanes.
Mid Wales and around Radnor Forrest can be quite a difference experience to open moor and mountain areas. Local people out hunting get lost if they get confused if the mist comes in, heard stories of riders landing up 30 or 50 miles from there intended destination, despite living in the area all their lives.
Many walkers see the real challenges in the national parks, yet there is a vast area of marginal hill land in central Wales which does not come into the popular menus of walkers. They may pass trough it following the signs of Offa's Dyke of Glyndwrs way, but they are passing complex and interesting terrain. The locals will tell of great feats of survival, but it is the conditions that are creating the challenges.