Oil and seasonings are the main thing.
For potatoes I may do the standard mix I use: salt, pepper, onion powder, and garlic powder. Then I may add Italian seasoning.
For broccoli, cauliflower, or broccolini, I just use that 4 spice mix.
For carrots I add some brown sugar and the 4 spice mix.
Whatever the vegetable; toss in olive oil, garlic oil, or your preferred oil, and season generously.
Then put on a pan with parchment paper on 375. Stir once or twice and turn pan around to cook evenly. The time varies greatly depending on the size you cut the vegetables, and the variety.
Broccolini will be done in less than 15 minutes, while carrots may take over 30.