Computer related:

• Don't be your family computer savy guy, you just found yourself a bunch payless jobs...
• Long desks are cool and all, but the amount the space they occupy is not worth it.
• Block work related phone calls at weekends, being disturbed at your leisure for things that could be resolved on Mondays will sour your day.

Buying stuff:

• There is expensive because of brand and expensive because of material quality, do your research.
• Buck buying is underrated, save yourself a few bucks, pile that toilet paper until the ceiling is you must.
• Second hand/broken often means never cleaned, lubricated or with easy fixable problem.