I've made my greatest (and fastest) gains ever on bench from doing Smolov Jr. largely because I became so familiar with the movement. Obviously this program is insane and not meant to be run often...
IMHO, increasing frequency and just becoming efficient at the movement will help your bench so much. In addition to doing 5/3/1 on bench day, I do another 'speed' bench day with straight weight and ultra wides (wide for me at least) with lots of rowing on this day. Tricep and pec accessory work on the main bench 5/3/1 day. In terms of accessory work, I've taken some pointers from this interview with Ed Coan:
Now let me clarify that I'm a small motherfucker (I compete in 148lb weight class, best competition bench 265...hit more in the gym but as Ed says in the interview that doesn't count for shit)..but right now I'm working toward setting some Jr. records in that weight class, so following the advice 'gain weight to get stronger' doesn't always apply to people's goals and especially not mine at the moment. So you can press more by weighing more...or become really good at doing the movement.
SPARK NOTES: increase frequency=profit