1 - Have a sketchbook with me at all times.
This tiny little 3x4 book fits in my preferred little hanging pocket of a purse.
This is my every day working toolkit - sketchbook and pens/pencils.
The slipcover (tutorial here) leaves pockets inside the cover that allow me to carry my 3x5 index cards as well as postcards of my artwork. I give out postcards rather than business cards - they tend to end up on a wall or refrigerator rather than stuffed away in a wallet.
When I want to really immerse myself in what I'm seeing I take time to not only sketch, but to paint. Sometimes I'll pull out a larger watercolor sketchbook, but often just carry along a couple of postcard sized pieces of watercolor paper.
2 - Stop thinking it has to be GOOD!
Start thinking of it as PLAY rather than WORK.
Open the book while waiting for an appointment. Just play around with a pen, or with shape, or with filling in the dark spaces.
Play with leaving space open, with different textures and patterns and lines.
Play with positive and negative space. Play with how much or how little you need to draw in order to define an image.
What are some of the obstacles that keep you from your sketchbook?
Are they self imposed?
What can you do to overcome them!?