My Best tios are :-
Make a detailed invetory yourself ,photo anything of value (Tables ,oven etc.)as proof of condition.
If you have just repainted stte that on the inventory.
Make your own arrangements to look after the garden , cut grass etc.
Make arrangements for a window cleaner on a regular basis - someone you know or use yourself who will alert you if there is a problem.
DONT use the letting agencies full service - its wasted money.
Make sure the pay by standing order each month = if they miss act quickly.
Do make sure you get at least 6weeks rent as a deposit nd when they give notice ask to view the property shortly after getting the notice.
Do the check out yourself with your inventory and photos (ask the agent to accompany you) deduct money if their has been more than fair waer and tare.
Good luck ,I've had some terrors and some angels.