Baseball, Kung Fu style.

Using a baton or an escrima stick will boost your empty-hand combat immensely. A baton forces you to move your arms like a whip with a weight at the end, being your fist. Choy li fut's "hammer at the end of a rope" is one of my favorite sayings.

The simplest whip punch is a jab. In kung fu, a jab's speed and suppleness are used for other types of punches and kicks. A baton will help you train your appendages to be loose but quick. Most importantly, using a baton in combat practice teaches you where your arms will end up at the end of your strikes.

Using an escrima stick to lightly hit body targets is a good and safe way to practice but a heavy stick responds better by giving you insight into striking effectively.  Heavier weapons are a great way to train your body to learn weight adaptation and impact. 

Practice combat with your partner weaponless.  You might tell yourself that using a baton against an unarmed partner is "overkill" but it's not about that.  It's about how your arms and body behave with the weapon.  Study how the stick behaves when used, then take away your weapon and mimic your movements unarmed.

Use wooden weapons and always practice in slow motion.  A slight lapse in concentration may lead to injuries.

"If you can't do it slowly then you definitely shouldn't do it fast." - I  say this so much that I forget where I learned it from.