To pass my road test I had to double clutch. Due to truck transmissions being unsynchronized I can float the gears. Which is really nice in the L.A., Bay Area and Seattle traffic I swear I'm spending half my life in. I usually only use the clutch if starting/stopping.
Non syncro or "crash" boxes should be double clutched. These types are Eaton, roadranger, Spicer. Most European gearboxes are syncro but don't be mislead into thinking its a euro truck so the box is syncro, some are fitted with crash boxes from factory. I have driven a wide variety of trucks and whether they are syncro or crash, I find it easier and faster to shift without the clutch. Many will argue this can damage driveline components but if done properly with experience, can be done with less component wear and quicker. I was taught this by my dad who with over 40 years experience and known for looking after his own and others vehicles managed to get 1.2 million km from a clutch in a kenworth, 6v92tta, 15sp o/d, 3.8:1 diffs. A younger guy in a western star, series60, 18sp, 3.9:1 diffs doing the same run and using the clutch as taught required a new clutch just short of 500,000 km. This was not due to age or experience as he also took similar pride in the vehicles, just purely worn out through use!
Something that may not have been mentioned yet is that most states when taking your CDL test you are required to double clutch during the test after that you can do what you want lol.
that may be the case in the states but here in Australia when I did my test for heavy articulated (semi) the tester told me to drive with or without a clutch, whichever I was more comfortable with, although if I did chose without and grind any gears it would be marked down as poor gear control so I decided to use it for the test. Once he passed me, I drove without the clutch back to the compound without any problems.
Some companies also require double clutching during your training and road test to qualify to be assigned a truck. Again, once you've qualified and are in your own truck it is up to you whether to DC or not. IMHO being able to either DC or float is valuable. Each technique helps the other. Bottom line either way is you need to learn how to hit the correct rpm.
When I did my driving test in Saskatchewan we were required to double clutch yet in Alberta I believe you can float shift, I like float shifting yet off road especially in mud clutching works better
The schools will teach you to double clutch, so you can pass the state driving test. Most, if not all, states follow the federal rules on testing for double clutching skills. Once you learn double clutching, you will find that it works best for you until you have driven 20,000 miles or so.....or do a lot of in town driving where you shifting all the time. Once you have enough experience driving with double clutching, you can start working on shifting without using the clutch. You may find you still need to use the clutch to move out of a gear if you don't time the start of the shift at the same time you let off the throttle. Start practicing with the gears on the high range side first, as they seem to be a little easier to shift. Keep in mind you still have to wait almost a second when upshifting for the rpms to drop down to your transmission speed. Also, if you have an engine brake, make sure it is turned off, otherwise your timing gets really messed up. The engine brake allows the engine rpms to drop really fast and you will have a harder time getting the shift done. I assume by shifting like a pickup truck, you mean single clutching when changing gears. You can do that, but again you need to have a good amount of driving experience and it would be a way to transition away from using the clutch at all.
I think the best way to transition from double clutching to floating is to "single clutch" or "tap out" of gear, then float into the next gear. I often use this method when downshifting on a downgrade or shifting on a climb. Hitting the clutch helps disengage from a gear when the drive train is under load. Once disengaged then float into the next gear. After learning that technique then you can start getting a feel for how much you need to get off the throttle to get it out of gear, then you are starting to float.