I clip Linus' whenever he starts to get stabby just walking on me, say once every 6 weeks.
He's a beautifully natured cat though. He's only been having his claws trimmed for the last 2 years or so, even though he was already an adult cat when I met him (BFs cat), but unusually for a cat that was never trimmed as a kitten, he loves having it done. As soon as I grab the clippers he comes running, purring as loud as he can, because it means he gets pats and attention and then some treats. The only issue is stopping him rubbing his face on the clippers long enough to clip.
He was exactly the same when he got a big cut and BF had to clean it with saline. He purred loudly and tried to rub his face on the cloth and BFs face and hand and on the bowl. He was just so ecstatic to be being paid attention to.
You'd think he was starved of attention but he really isn't, he just can't possibly be loved enough, though only on his own terms and by his people. He's such a biddable and loving cat that we taught him to sit on command within a week of starting training.