I had this issue a few weeks ago while performing. I had a gimmicked card I was going to use, but I was going to do some other effects before it. I put it in my jacket pocket and did some effects, and while people are reacting I casually palmed the card off (or sometimes blatantly grabbed it out), put it in the deck where I needed it, and did the effect. So yes, palming helps, and maybe a jacket pocket would work better than a pants pocket since it seems less shifty.
Jacob