Keep your eyes open. There's things to see everywhere. I've not been up there this time of year but keep an eye out on the beaches and just offshore for plover, sanderling, dunlin, terns, gannets, oystercatchers - the list goes on. I've seen a lot of auks, divers and mergansers along the coast but I don't know what will be there this time of year. Sea eagles breed along that coast so there's always a chance of seeing them, and if you like walking the glens to the inland lochs give you a chance of golden eagles and deer. I'm not sure if you'll still get the sandpipers and golden plover on the moors this time of year. There's red kites but they're nearer Inverness. If that's the way you're travelling up keep your eyes open along the A9 and the road west from Torr roundabout because that's where you'll see them. There's what I presume is a feeding station along there but I prefer to see them in a natural way. If you're around Gairloch (south of Ullapool but a very scenic drive - just allow plenty of time) look up the Gairloch Marine Wildlife Centre down at the end of the quay. Ian does boat trips out into the loch. They're seeing a lot of dolphins at the moment. He'll also be looking for birds, seals and whales. Though the whales are mostly further out in the Minch I've seen a minke from his boat. Also maybe en route Loch of the Lowes just a few miles out of Dunkeld - the pair of ospreys have 3 young, but check the SWT website first as they can't be far off leaving.
Enjoy - it's a fantastic area.