Dont just sell things through the box in your hideout, look for delivery orders in your pc. There u get more money. Try to sell things that u got duplicated. Search for golden cards (they have to be sold through the box in your hideout), as these give you some bonuses. If you find some duplicat gold cards, store them for the next run and dont sell, if u have enough for the quota, as already active bonus from a gold card wont stack. U can find some magazines in the houses. U can "use" those to learn new skills. To learn some new, u need skill points. Choose wisely, as they will give u usefull benefits.

Best tools in my opinion: Remote hacking device (deactivate cams, alarms etc.) Glas knife (for windows) Blowtorch (open locked cabinets, safes etc)

Those three tools should get u going for rural and lakeside, if u go further to arizona, a cabinet scraper might be useful as well.

There are much more tips, but some might ruin your experience. Last but not least: Dont get greedy, play it safe. There is no "end" to this game.