Don't forget a bit of physical activity. You don't have to go crazy, but maybe a nice brisk 20 or 30 minute walk maybe an hour or so after you've had iftaar...it'll do wonders for your energy level and it doesn't hurt the old waistline either.
I like to hop on the treadmill with my Ipod playing a lecture (Imam Humza Yusuf being one of my favorites).
:)