Probably the simplest approach (and the most scenic, is via Gougane Barra, where there is ample car parking around point W09103 65913 A (as well as a pub, hotel and toilet facilities.) Proceed up the Beara-Breifne Way track and simply follow the zig-zagging trail for 3km, which leads virtually all the way to the high point. As you ascend the views over Gougane Barra Lough and the surrounding landscape are first rate. The summit is a slightly raised mound. Linkback: https://mountainviews.ie/summit/1448/comment/18076/

View from Foilastookeen/Gougane horseshoe of the Gougane Barra Valley and Forest park with Bealick in the distance. Linkback: https://mountainviews.ie/summit/1448/comment/18762/

Parked at a a double gate at W054 647 B, just north of Gowlane Bridge on the road west of Conigar in the Borlin Valley (space for a single car). Hopping the gate, a farm track pointed the way uphill for a short distance. I aimed for the left of a low band of cliff on the horizon. A handy fence provided a guide over Conigar’s NE shoulder. Descending on the other side, I passed tiny Lough Glas, and continuing alongside a fence, passing the even smaller (and curiously named) Lough Namrat. At this point I realised there were trail markers for a track running alongside the fence - the Beara Breifne Way - as a small sign later indicated. And several hundred metres ahead I could see another walker crossing the summit of Foilastookeen.
It wasn't too difficult a climb to the summit - a broad area of heather and rocky outcrops. And grand views, especially north where steep cliffs drop down to Gougane Barra.
Returned by the same route, ascending back over the shoulder of Conigar and made the easy descent back to the car in about 2 hours. Linkback: https://mountainviews.ie/summit/1448/comment/18159/

One of the advantages of starting or finishing an ascent from Gougane Barra, as it presents stunning views over the lough, especially on fine summer days, and you can also have pint if you've just descended here! Linkback: https://mountainviews.ie/summit/1448/comment/23528/