My 2 cents...
- Microfibre wash mitts (If you drop it, bin it - or wash thoroughly and keep it for your wheels)
- 2 buckets
- Waffle weave drying towels (chamios run the risk of dragging bits of dirt that blow on to your car post wash across your paintwork)
- Wax regularly to provide an extra layer of protection
- Strongly consider a professional detail every 1-2 years with either a hand or machine polish depending on the condition of your paint. DIY if you are handy and have the time.
- Has already been covered on this forum, but never let the dealer / mechanic wash your car!