The core of living more sustainably is: rethink your need for a product or resource, reduce your usage of it, reuse it if possible, and recycle it whenever you can. Here are some of the simple, cost-effective ‘green’ items you could use.
Zero Waste Nerd: A Zero Waste Kit. But perhaps this kit would be good for people who eat out a lot (and really really love straws! I never buy bottled water when out and I rarely buy food out (it's cheaper to bring my own from home).