By staying Flexible
With all of that heavy lifting and strain on your muscles, it is very possible you are reducing your mobility.
BUT WHY does this affect my lifting?
Because of length-tension relationship of muscle fibers. Scientific observation states that muscle fibers at different lengths will produce different amounts of force and there is an ideal length which is LOST if you do not stretch when lifting heavy.
After a heavy lifting session, your muscle fibers are in a shortened state so dedicating time to stretching will ensure the muscle fibers remain at ideal length to effectively contract during your next training session.
Some of my favorite dynamic stretches to try:
1) Cat Cow
2) Forearm Plank to Dolphin
3)Walking World's Greatest Stretch
4) Plank to Cobra
Work it out and stretch it out.