Alternatively take the old railway to Threlkeld, up the valley almost to Skiddaw House, then come back under Lonscale Crags, and down the trees on the side of Latrigg.
Good route but the bit of track under Lonscale is not for the faint hearted, in fact I've never seen *anyone* clear it so she may not thank you for that part of it... It WILL involve pushing/carrying. Nice route though, decent views if the weather is good.
Another option would be a simple round-the-lake. Starts out on road heading south towards Borrowdale but you can quickly get onto a footpath (bikes are sort of allowed) on the right hand side, take you down through woodland eventually to Grange at the south end of the lake. Couple of nice cafes there then come back via Cat Bells (bit of pushing to get up there but easy once you're there, nice views)
You join it HERE then follow the Allerdale Ramble path then a few easy bits of quiet road and across a field back to Keswick.