Personally I have found that mutual masturbation is a great activity for those lazy days, when you really don't want to crawl out of bed at all. Lying beside each other it's fairly easy to reach over and run your fingers through his pubic hair or skim your fingers lightly over his balls and cock. As you play you will notice that his cock will arise to the occasion. At this point if he hasn't already started to work his hands over towards your pussy there's nothing wrong with grabbing his hand and directing it to your pussy yourself. He'll get the idea.
Lubrication is always a good idea.
If there isn't enough lubrication then sensitive skin can become chafed and extremely uncomfortable. Now there are many different types of lubrication that you can use. Some of the choices you will make in choosing lubrication might depend on whether or not you're going to indulge in oral sex afterwards. If this is the case then you want to use something that will at least taste good and not leave a bad taste in your mouth. There are lots of love lotions available from the sex shops that will fill the bill here.