After about 100+ hours in game I've decided to share some wisdom. Stuff that I've found out through experimentation to enhance the ATS experience. This guide is focused more at new-ish players, but hopefully even folks that have been playing for a while will get something out of it.
Controls and Configuration (Gamepad)
I use an Xbox One controller and these settings help out a lot. Set your triggers to acceleration and braking. Set your right stick to look. Increase your up/down look deadzone significantly. This allows you to slap your look stick left and right to scan intersections quickly without accidentally ending up staring at the floor or roof of your cab. Increase your steering sensitivity. Matter of taste, but the default steering is just too slow for cornering at speed. If you find yourself braking mid turn to wait for your steering to catch up, this is a must.
Efficency
Cruise control - Use it. I played about 10 hours without it and I can't even guess how many speeding violations I got or how many times out of fear of getting them I travelled under the speed limit costing me time. Building on that, set your cruise tolerance to zero, turn on auto retarder.
Watch the speed limit signs though, especially in areas where speed cameras are common. Running with cruise control it's easy to get in the zone and miss a speed limit sign.
Sleep efficiency - There is no such thing as a partial rest. Every time you rest it's going to burn 8 hours, even if you're not that tired yet. Start looking for a place to park after the first yawn, no sooner. You'll be fine.
Hit F6 to see exactly how much longer you have before you get sleepy
Most jobs will allot you enough time to sleep once, especially after you put a few points in the long distance skill, which you'll want to do early on. For the really long jobs you'll have time to sleep 2 or 3 times and have time to spare for checking out new towns along your route.
Never travel empty - When you go to job selection, click on the dot on the map for the city you're in. This will list ONLY jobs originating in that city. If there are no high paying jobs, just grab a short distance job to a nearby city and try again there. And remember, $ per km is what you're after, don't just grab the highest total payout.
One additional tip on efficiency: On long trips you can and probably should edit your route. Open your world map once you've picked up a job and drop pins (waypoints) in towns right near your route that you haven't explored yet to unlock the truck dealerships and recruiters there. The little time it takes won't make you run late on the long jobs.
Your Rig
Your first truck- Get a Peterbilt or one of the other trucks that starts with good baseline HP. Trust me, it's worth saving up the little bit of extra money when you're not crawling up hills, or when you're driving stop-and-go in the cities. Once you get the later engine upgrades it's incredibly satisfying passing the trucks that are struggling up Hills.
Necessary upgrades - Money early game is tight. Upgrade your engine as they become available, also your tires. Grab a transmission with retarder equipped for the cruise tip above. That's all you really need. Allison 6 speed trannies are garbage, don't waste your time.
Unnecessary but helpful upgrades - Put a light bar on the roof with a couple aux lights, but bear in mind they only work when your high beams are on.
You'll have to open the light menu (default F4) and check the blocks for aux/roof lights to enable them.
Also get side skirts and a bull bar. These will dramatically reduce your damage when you inevitably cut a corner too sharp, get sideswiped in a roundabout, whatever. They pay for themselves quickly.
Starting your Business
Unless you've played before, wherever you chose to put your home garage chances are you're going to end up hating the location. Don't bother upgrading it. By the time you can afford your first garage, you're going to want to move.
San Francisco is a great first location. Low fuel prices and lots of close-by cities to trade with.
Buy a garage in a good hub city and move there. Once you've moved, sell your starting garage. Buy your second (and third, if you can afford it) trucks and put them there. Buy Peterbilts for your fleet trucks, at least at first. There is NO benefit to buying better trucks for your hired drivers. None. It makes no difference at all. Tip here, if money is super tight you can change the paintjob to a cheaper color to save about $500 per truck. Strip off optional accessories like the sun shield and front mirror to save even more valuable cash.
Once you pay your first truck off, take the loan. Not the little loan. The 400k loan. It has the lowest interest rate. More on that in a minute.
Then hire and assign your drivers - Try to start with drivers that have at least one point in long distance and one point in ADR. If none are available, no worries. Grab whoever and assign them to trucks. Manage them and set them to focus on ADR or long distance until they have a point or two in each. Then put a point into each of their skills (Except Eco, don't sweat Eco yet) to maximize their job opportunities. Don't want them returning bobtail either.
Back to the loan - The 12% interest on the 400k loan works out to .. Well math, but it's less than 2k per day.
If you have 2 drivers they'll make about that right from the get-go, so the loan to start your business basically pays for itself.
And within a few days their skills will increase and they'll be making more than that, so you're already profiting. If you wait "
I don't need no BANK to pay my way" you'll be losing out on a ton of potential profit. Don't worry about paying the loan off early, just use your revenue to keep expanding.
Assorted Tips
If you have a music folder on your computer, you can create a shortcut to it and drop it in the documents\ATS\Music folder to access your music in game.
Then hit R to bring up your radio. You may want to turn down the music volume to where you can still hear the truck though.
Never skip skilled parking your trailer - It gets easy after a while and the experience boost is worth learning to do it. Matter of fact, just go into the gameplay options and set it to skilled only. Pop-ups ruin the immersion.