What's the best way to add progesterone?

I am going to try adding in some more progesterone- something a little stronger that the OTC cream I've been using. Is the best way to do this just all at once or can you sort of add it in slowly, gradually increasing the dose? I know people say you will feel worse before you feel better.
What is your opinion on the best form to take it in? My doctor wants to prescribe Prometrium at 100mg before bed to help me sleep. If you use the cream, what dosage do you use and does it matter if you use it once or twice a day. I'm not sure if progesterone has a longer half-life than estrogen or if it build up over time.
Your opinions are greatly appreciated.

I am partial to the creams myself as it is easier to adjust the doseage. I use a 5% cream. In the beginning I did need to use it 2x per day, but currently only use it 1x per day. Gradually increasing the doseage is the way to go, whether it be estrogen or progesterone. IMHO if you use a cream, it does have a build up effect. At least that was my experience with the creams.

I use Prometrium and love it.

100 mg at night. I take it about 2-3 hours before bed and I sleep like a baby. I take it for three days and then off for one because the half life seems to be so long. Progesterone half life (how long it stays in your system) differs depending on how it is transported.

I had to experiment with this part to find out how often to take it. ...every day was too much.

I have tried OTC, Prometrium and Compounded Progesterone Cream. All three are good forms you just have to try each one until you find one that works best for you. I like the Compounded Progesterone cream the best you can adjust your dose. I use half a dose in the morning because I can notice a difference in my symptoms during the day and then the full dose at night for a total of 75mg a day. I am on the high side. I would start lower like you said and work up until you get the best effect. Everyone is different.