Warhammer 40,000/7th Edition Tactics/Movement 101

This page indexes how movement works in 40k:

How Movement Works

You measure. You move. Six inch movement, 12", or running? You decide. Most weapons can't fire after moving 12", instead making a Snap Shot at BS1.

Vehicles must pivot on their center when turning, rather than moving to the sides.
Unless you have been Rammed by another vehicle, you may not end your move within 1" of any enemy unit. Unless you are a Skimmer, Jump Infantry, Jet Infantry, or Jetbike, you may not come within 1" of an enemy unit.

Unless your strategy depends on it, keep your units from being strung out. You never know when an enemy may change tactics and a unit may need fire support quickly.
Unit cohesion means models in a unit must be within 2 inches of each other, but that doesn't mean you want your blobs of troops in base contact at all times. Keep your models in loose formation; horrible things happen under blast templates.
Remember, every inch counts. If you run and you roll a 1, tough, one inch can reform your entire squad from a jumbled mess to an orderly squad in tip top shape.
Good god people, remember when moving your vehicles and walkers to remember what side their heaviest armor is on. So if you have a Leman Russ and you see the enemy has Lascannons, point the front of the damn tank towards them, or eat shit and die.

Use a tape measure. As of 6th edition you can measure anything at any time.

Someone who wants to flee will attempt to get away any way they can. Do not focus on directly pursuing an enemy unit, instead you should cover their escape routes.
- Sometimes, the bait they throw out to cover the retreat of their unit is worth killing, even if it's small-fry by comparison.