Often done as part of a circuit including Ben Beg and the Bunacunneens, it could also be done in isolation. One approach is from the north, where a farmer has previously given permission to use a track starting at L963 569 A. This takes you to 200m ascent on the northern flank from there it is possible to ascend the steepish slope to the col about 800m NW of the summit area. Although the top is unlisted it has a decent cairn – something the NE top doesn’t. There is also a small, unnamed lough next to highpoint. Very good views all round.
Lugnabrick may also be combined with Knocknagussy, which is about 3km to the SE (see summary for that hill for approach.) Linkback: https://mountainviews.ie/summit/477/comment/5236/