If I'm below 100 million, I invest whatever gold I have into bids or items that I can flip for a profit. If I'm above 100 million, I look for an item to buy and put up on the RMAH.
What I want to do this weekend and for the next few days, is build up my gold balance to around a quarter million so that I can invest in more bids and items, especially now that I'm learning about some of the higher end markets in Diablo 3. The key to making money in Diablo 3 is knowing what sells, and right now higher ticket items are the way to go.
It will most likely take me a few days/turns to reach my goal of 250 million gold and I will miss out on a few days worth of RMAH sales, but I believe that it will be worth it. My plan is to move up from making $5 a day to making $10 a day with this investment in capital.
Also, if you are interested in participating in my dueling tournaments (when PVP FINALLY hits), sign up for my newsletter and I'll make sure to get you an update on how to participate.