A few of my favorite things...

1. A good foam roller.  These are so incredibly helpful to everyone but particularly to people who have to sit for work.  This is one of my favorites,

Standard Pro-Roller

2. Grip socks.  I always wear anti-slip socks while I teach and I recommend them for clients as well.  Here are a couple of brands I like,

ExerSocks

Great Soles

ToeSox

3. Resistance band.  Easy to take with you anywhere and a great way to stretch and stay in shape.

Theraband