I tried a few pills, but in general Cialis gives me weird vision side-effects and flushing, so I avoid it.
I take generic V sometimes.
It's not a pill, but to add on to what Bob said:
Sleep better.
Fix chromic stress and anxiety.
For those two, consider checking out Ashwagandha, EPA (Omega 3), and L-Theanine. (These are just supplements. Herbal, Fat, and Amino Acid respectively.)
Also, don't workout shortly beforehand. At least not anything too strenuious.
This was a tip from a provider... It was pretty accurate.
In retrospect, it makes sense the post-workout pump would mess with the other pump.
Similarly, caffeine might not be the best choice since it constricts your blood vessels (unless you drink coffee like water, then it just undoes the withdrawal effects, and dialtes them.)