Throughout my training I've always relied upon a gearmaster to shift.....

I had a Pontiac Sunfire with that. Probably one of the only Sunfires built with a 5 speed manual lol.

 

Most trucks you can add the mph numbers together = the gear if you get lost trying to find one.

15 mph 1+5. = 6th gear
25 mph 2+5 = 7th
Ect.

 

If you are driving a 2007 model year engine or later; watch for the needle to fall down to 1000-1100 rpm after each up shift. That will tell you you're on point. To down shift let it run low and down shift between 1000-1100 rpm. Modern engines, 2007 and later, make full torque from 1000-1500 rpm and you should use that entire range. What rpm to shift at varies a lot so just watch where the needle lands and over time you'll get a feel for it. Another post said use your ears; I find that to be great advice, especially when in low range.

 

does the truck not have a tachometer...

 

If you buy one new from gearmaster it's 695.00 according to their website. Not worth it.