- Get the Quadcopter ASAP. Run around and get some money drops in secure areas, they give you just about $20,000 a pop so you'll only need to hit up 3 or maybe 4. The game is much less combat-focused and built more around stealth infiltration (though you can be as loud and bloodthirsty as you like if you really want to), so all you really need for a firearm is the Core Dump Pistol (silent and scoped), or the Zero Day Rifle (same, in rifle form).
- Once you get the quadcopter, treat pickup icons (aside from key data) in the open world as entirely optional diversions. After you get the quadcopter, money is only used for vehicles, weapons and clothes, none of which are essential to making it through the game nor particularly expensive. Similarly, the game throws research points at you by the dozen for beating the main missions. Paint jobs are purely cosmetic.
- Use the Jumper to infiltrate if you just need to do a Physical Hack (the USB icon), because it can do those, and any alarms raised are for the Jumper and not Marcus.
- Get the Wall Hack skill for the Quadcopter, it makes recon on mission locations much easier.