Well, seeing as how I'm married to my 'ler, I just need to ask him or tell him that I want him to tickle me.
I've been getting tickled just about everyday. Over the past weekend, not so much as we were fighting and he's battling a cold. But other than the occasional fight, he'll divulge my tickling "fix" every day. Whether it be quick pokes when I'm getting undressed for bed and he tickles my sides when I'm changing my shirt. Or if it's him coming home from work and I go to hug him and he grabs me and tickles me for a few minutes until I'm breathless.
Plus, he tickles me as foreplay between us.
So, I guess I can say "on a regular basis".