1. Look for an alternate route.
2. Decide whether you really need/want to cross the mud. If so, determine what to do if you start to become stuck. Plan how you can recover a stuck vehicle.
3. Carefully survey/reconnoiter the mud. It does not hurt to stop your vehicle to study conditions and plan your attack. If necessary, do so on foot. You do not need to wade through it to evaluate the conditions.
4. If you are planning to cross the mud, accelerate to a moderate speed before entering the mud such that your momentum will help carry you through it without becoming stuck. Be sure that you can control the vehicle at that speed under such conditions. As long as it is safe, be sure to maintain your speed as you cross the mud.
5. After crossing significant mud, be sure to wash the mud from the underside of your vehicle at your earliest opportunity.
Good luck,
John