I use ebay all the time, I find it easy and useful to sell and buy.
If you put items up for sale never select the automatic list and relist option or the ebay system will automatically list your items each time at 10% less and will let buyer make you an offer. Always do it by yourself manually.
Yes they charge for their services but no more than what you pay at bring and buys, it all mater of choice, selling on ebay you get a wider costumer base.
Make it clear how you do postage, explain to international sellers what their postage costs, combine postage on multi buys (this does not work if you or the buyer is signed up to ebay’s international postage service), inform buyers what you are doing
Always post items tracked and signed for, I use second class tracked and signed for, £4 gets you up to 2 kilos weight on a small parcel UK wide, France for the same weight is £14.
Always have payment via Paypal it is safe and convenient for you, you will get people asking you to take cheques, Postal orders, cash always refuse Paypal only. You will have people asking you if your starting price is the lowest you will sell the item for, I never reply they are always time wasters.
Always put up at least 6 in focus photo’s of the items you are selling, also a good explanation of the items you are selling.
I always post items within two days of payment received, never post items until they are paid for via Paypal. Always send tracking information via Paypal or ebay.