Ok, I know I'm a bit late to the party. But I'll throw my 2-cents in, esp given the OP's debrief on how it went down.
Learned this one from a slightly older, much wiser 4.0-singles mentor: when you're tired or in doubt, hit cross-court, regardless of if it's a FH, BH or change-of-direction.
The reasons are many including the obvious ones of going over the lowest part of the net, giving yourself the longest "in" shot and keeping the stress less on all parts of your body/swing. But what it's meant the most to me is...that it erases any indecision. The older I get and the more I play, the more errors I seem to be making when I "change my mind" and can't get the footwork or racquetwork to catch up with my brain.
Anyhow, lotta good tips in this thread...and I'll be sure to visit it when I need a little boost. Good topic, OP.
A 3.5 masquerading around with a 4.0 mask on.