2 add to the above
Budget 10-15% for ebay’s fees, and get your Paypal account set up before doing anything, if you don’t already have one.
Have a look at completed listing to get an idea of what you things will go for.
Make sure that you pack stuff well when sending, and don’t be excessive with what you add to the P&P costs for this, I look at between 50-75p for packaging materials
For finishing times, evenings are the best, I avoid Friday & Saturday nights, between Sun – Thur, I find it varies every week to what goes well on those.
Wouldn’t use reserves either, as the fees on them are very high.