Mobile Rv tech-warranty work-do you guys tip????

If I am on the road and the shop works me in, I consider tipping based on the attitude and quality of workmanship. If the tech makes me feel like I am an important customer when I pull up with my rig and starts working right away on my trailer. It also depends on the tech's attitude, is he positive and friendly. Is he willing to help me understand the problem, give me suggestions to prevent the issue in the future.
If the work is just a regular routine job and in my home town, I don't usually tip.