At Sligachan on the A87, the A863 heads west towards Carbost. On this road, just behind the hotel there is a long layby with ample parking for several cars. Do not block the access to the Mountain Rescue building. If there is no room, then there is no objection to parking in the hotel car-park.
Sgurr nan Gillean via the 'Tourist Route'
From the car-park, cross the road and get onto a path. The path crosses the Allt Dearg Mor via a narrow wooden bridge, then heads up towards the Bhasteir Gorge. After another 2km, another narrow bridge is met, use this to cross the Allt Dearg Beag, then head up the recently repaired path towards Coire Riabhach. Continue up a less well defined path up boulders and scree to come out of the coire, then start veering right. As you start facing south-west, the path climbs more steeply by a trickle of water, which can occasionally only be heard beneath the rocks. When below a small butress, the path splits - keep left, then continue, with occasional scrambling, onto the south-east ridge, otherwise known as the "tourist route". Stunning views of the southern Cuillin abruptly open up, but concentrate on your feet ! The route is obvious at first, more or less sticking to the centre of the crest. Further on, the route comes to a steep climb - you may be tempted by routes to the left and (less obvious) to the right. Both are feasable, but if conditions are dry and windless, I find it simplier and more enjoyable to keep to the crest. Up onto an airy platform of red rock, the small summit is reached by a bit more scrambling and bridging of a small awkward gap. The views are amazing in all directions.
Sgurr a'Bhasteir via Gillean's West Ridge
Looking west from Sgurr nan Gillean's summit, the route down in not particularly obvious. Look slightly right and you'll see how to continue to the ledge below. Once onto this ledge, cross onto the south side of the crest and climb through a hole in the rock. Turn left and the route down becomes clear and straightforward for a fair bit of descent. Progress along the ridge eventually becomes blocked - look right and you'll see a drop down a long chimney. Called "Tooth Chimney", this 50m drop quite often has a sling or two in place at its top left by previous climbers. Abseil down to the bottom of this gash onto a ledge below, then head south-west along the ledge to gain the scree covered top of Bealach a'Bhasteir.
Head up along the crest towards Am Basteir's east ridge. When the easier terrain has been passed, keep slightly to the left of the crest on a worn path. Start climbing again and get back onto the crest. You'll be faced with a short awkward drop, aptly named the "Bad Step". It's not as bad as it looks - just descend facing the rock, feeling for the holds and drop directly to safe ground. Am Basteir's airy summit is just a short walk up some solid rock and stones.
Bruach na Frithe
An abseil and airy, tricky scrambling are required to continue directly down to the Basteir Tooth and beyond. However, it is easier and quicker to return along Am Basteir's east ridge to Bealach a'Bhasteir, then drop on scree towards Choire a'Bhasteir and turn west to climb up an obvious path up more scree around the base of Am Basteir's north face to reach the top of Bealach na Lice. The Basteir Tooth can be bagged from here - head down a few metres into Lotta Coire to near the bottom of the screes, then look for a narrow ledge sloping up to the Tooth's summit. Sgurr a'Fionn Choire is a fine viewpoint and is worth a detour - just head more or less directly for it, some easy scrambling on the way. To get to Bruach na Frithe from Bealach na Lice, follow the worn path around Fionn Choire to the gap between Sgurr a'Fionn Choire and Bruach na Frithe, then continue along Bruach na Frithe's east ridge with no difficulties. Bruach na Frithe is the only peak on the main Cuillin ridge to have a trig point, from where views are stunning.
Return to Sligachan
Head back to the gap between Sgurr a'Fionn Choire and Bruach na Frithe, then drop into Fionn Choire using the worn path through the sections of scree. Once in the coire, follow the path down, picking up a burn to a grassy area at around c600m. Head north-east off the path, climbing slightly to Meall Odhar, a minor flat top to the north of Sgurr a'Bhasteir. Sgurr nan Gillean's Pinnacle Ridge dramatically comes into view. Aim north-east to drop onto grassy ground and pick up the Coire Bhasteir path to follow back to Sligachan.