Just keep your schedule flexible, be open to making adjustments if things don't pan out, as others have said 50/50 might work better. Regarding eating, you're not a monk so no need to not eat after mid day and sleep on a low bed, but it may help to limit your intake of food and be mindful of your portions. Overeating is what induces sloth, not the times at which one eats - That's just my experience anyway. Avoiding entertainment such as TV, games, books (other than Dhamma) and computers, cologne/perfume (and other sensual smells), and any other activities that draw one into the sensual realm would naturally be very beneficial for your retreat. That would naturally include avoiding sex/masturbation for the duration of the retreat. So that's uh, 6 precepts all in all
6 very good ones.
- Killing/taking life
- Sexual activity
- Stealing/taking what is not freely given
- Intoxicating substances
- Entertainment, garlands (cologne, body spray, smellies)
I think that's a good level of sila for a self retreat. Perhaps you are one who likes to formally receive the precepts from a monk, perhaps you have your own precept ritual or perhaps you like to just make a mental determination to do so as I do. Whatever the case precepts are tools to be used to further one's progress. You can't have Pannya without Samadhi and you can't have Samadhi without Sila, so it's very important
You may even want to find a recorded retreat on dhammaseed or one of the many audio dhamma sites you can find a list of sites here
. This would include a morning/evening dhamma talk into the fold, and you could even mix and match and work on a theme for the retreat, or pick out talks as you go along according to a subject you feel you need some guidance on e.g. viriya or something.
That's just an idea though.