It's vital to keep on top of the garden as well as sorting out the inside of your home.
Once you've started cutting your lawn after the winter break you must keep going. It can be quite a chore, especially if you've got hedges to clip too. But it's so important as a house selling hint to keep the outside looking neat.
If the outside looks uncared for then people will approach your house warily thinking that you also don't care for the inside of your home.
If you hate mowing the lawn then consider paying someone to mow it for you. Either professional gardeners or odd job men (or even your own or a neighbour's teenager!) will cut your lawn and hedges.
Also if you don't care for the garden it makes it look hard to manage and therefore detracts from the value of your home.
Paint fences if you have them and make sure they're in good order.
Think about the area around your home too. If there are alleys are they tidy and clean of graffiti? You might find that they're not and if so, contact your council to get them cleaned up! Every bit of your neighbour hood is important - you never know when someone will walk to your home and go via one of the local disaster spots.
Report grafetti - you can often do it online by email which makes like easier. Check it gets done and if not, chase it up!