How to spend less while working?

Commute the cheapest way Public transport or cheaper parking opposite your office or better still car pool with friends and colleagues.

Spend longer time working if there's no other thing to do. In that case you save electricity cost at home, less likely to waste your time in front of the tv or shopping and polish your working experience for a promotion.

Pack lunch from home  Lunch take up a portion of our spending and packing from home may be a cost saving measure for a family. 

Make coffee and milo from office pantry 

Eat as much meeting refreshment items as you could and skip lunch.

Eating out? Go in a group where someone else drive. 

Block shopping websites on your laptop. Delete shopping app on your mobile.

Wear the same fashion every 5 days.

A just for fun write - I don't think anyone can do all these although you would really save quite a bit.  Could you?