The walk from Loch Morlich up to Rothiemurcus Lodge, where I once encountered a friendly dog (but that's another story), is a good one, and if you are feeling energetic you can head on up to the Chalamain Gap and follow the path to Sugarbowl at the foot of the Cairngorm ski range.
The walk from Glenmore to Ryvoan bothy is a nice low-level walk too.