Keep everything moving all of the time.

You will swim good quality backcrawl if you keep your arms and legs moving.

Make sure you maintain fast continuous kicks and keep circling your arms.

Remember, try to improve one bit of the stroke at a time.

Once you think you have done all of these things spend a few sessions practicing them and then have a look at intermediate backcrawl.

Introduction

Basic: Step 1

Basic: Step 2

Basic: Step 3

Intermediate level

Advanced level