If you kick the drift off before the flare, you will need to put the into wind wing down and land on the upwind maingear first, otherwise you will get the drift you mention. Otherwise, kick the drift off as you flare and still stop the drift with into wind aileron. As Dave says, it just takes plenty of exposure! Make sure you don't shy away from having a go if offered the choice of sectors and TELL the captain you are not overly experienced BEFORE you make the approach. That way he will feel more comfortable with things not being perfect whilst you practice and will be even more ready to 'offer assistance' should it be required!
Make sure you ask for feedback afterwards too, as he may be able to help you pinpoint why something didn't go as planned. Most good captains are willing to offer advice if asked, but many won't offer it unless you DO ask, unless of course it is a training flight!
PP