Well, lads; I was introduced by one of my Regulars to a 4-hour daytime session as a better VFM alternative to Overnights. [I'm not paying for her to sleep next to me!]
I'm fairly sure the OP isn't one of those who was looking for some E. L James-type erotica so the following is a rough guide to the sort of things that this Regular and I get up to on a 4-hour session [without timings, of course!]. The next one's due in about 6 weeks time and when I confirm the arrangements, I must remember to ask her if she has her own chessboard or should I bring mine?
What we tend to do once the she's locked the front door behind us is have a fully-clothed good old tonsil-tickling DFK session in the hall [I see her regularly but not that often; roughly once every three months] before going through to the bathroom for a clean-up and then joining her in the bedroom. By this time most, if not all, the clothes are off for a protracted session of foreplay, including oral both ways. Obviously any clothes which were still on at the start of this will be on the bedroom floor by the end of it! This particular WG's one of the best I've met at delivering BJs and that leads us on to fucking. After a bit of a breather, as she seems to enjoy my RO nearly as much as I enjoy her BJs, we usually have a lengthy session of that.
Before I've arrived at her place, she's either made sandwiches or bought some from her local supermarket and we eat them during a short lunch-break with a cuppa for each of us and a ciggy for her. This is all "off the clock" and allows us to catch up with what's been happening to the other since we last met.
She'll probably have another ciggy before we begin our second longer session in the bedroom, almost always with a prolonged "tie 'n' tease" session. Because I'm a Regular client and because she knows I enjoy this, she seems to enjoy providing it more than many of the girls who've tied & teased me in the past. I'm not saying she takes a sadistic enjoyment in teasing me this way but she certainly makes sure I'm primed for another bout of fucking at the end of this activity. Some more post-coital chat and laughter will usually be followed by something like "69" and a not-always successful attempt at a third fuck before we call it a day, usually because I'm shagged out both literally and metaphorically.
As with Overnights, this is something I believe you can only do well with someone you've seen at least once before for a shorter time and where each of you feels comfortable with the other. I also think that vorian's right when he says that you can enjoy the build-up to the activity more in a longer session. I'd also add that the WG I see for these protracted sessions is generous with her time; including a 20 minute or so lunch break, my 4-hour sessions with her have always been closer to 5, than 4, hours in total.