In reply to sweenyt: About the best Glyders day I can think of would be something like:
From Ogwen head into Cwm Idwal, take the
Direct Approach to Senior's Ridge (Grade 2) into Cwm Cneifion, head up
Cneifion Arete (Grade 3) traverse around Y Gribbin into Cwm Bochlwyd, up
The Chasm Face (Grade 3) and over the summit of Glder Fawr and down
Bristly Ridge (Grade 2) traverse down and round to heather terrace on the East face of Tryfan to head up
South Buttress (Grade 3) to the summit of Tryfan and then descent down the
North Ridge (Grade 1).