Any good tips on properly preparing a bed for spray in liner??

[UATahoe]

Thought i would ask those that have had good success with spraying in their own liner. I recently purchased the Raptor bed liner kit and was going to tackle the job once it got a little cooler. I hear most say that the durability and final outcome is really all in how you prep and how well you prep. Anybody have some tips on what worked well or things they would have changed?