1Gr8Life,
I've enjoyed a long, positive relationship w/ AMEX (both Green & Blue). The biggest piece of advice I can share from my experience is already in your siggie...always, always, always PAY ON TIME!!!
I use both cards regularly and (just like you) I oftentimes make my payments early (though I've adjusted my timing & amount from pointers I've learned from my forum family)! As with all CCs, just use your AMEX wisely, pay your obligations on time, & you'll be fine.
Starting Score: (1/31/13) EQ 759...EX Plus 778...TU 777 (~38% util) 
@Anonymous wrote:Fico Forums is Great! However, I often end up with even more questions then when I started reading. LOL
Curious... I have AX Gold Rewards Plus card less than one year. Any advice out there with regard to how to best please the AX gods into remaining one of their favorite users? (ie: I use card to auto pay 3-4 other bills every month to get the max reward points. I often pay before the due date and when I receive their email note that it is going to be due. I pay the balance not just the Statement Balance due.)
I like AX and want to establish a long and happy relationship for both us us.
Amex and I go way back to 1987. I have a green, blue, and clear. I am one of the few happy Amex cardholders on myFico. 
My CLs total $50K, plus the green.
My advice is to regularly use the cards and PIF. Repeat. Repeat. If you are going to make a large charge, call and give them a heads up. Same applies if you will be traveling abroad. I always call before a trip and tell them I will be in country X and using the cards.
Revolving a balance with them can be tricky. Try to avoid this, although it can be done if you have a long history with them. I still have a balance of about $2500 at an incredibly low APR that I have been revolving for quite some time. I have yet to see any AA.