The outside of your home can look great without you having to spend too much money, but it will take up some of your time. If you don't have any to spare then hire someone to do a couple of jobs for you. It will take a weight off your shoulders because you won't feel embarrassed when people walk past. This is even worse when all your neighbors keep their garden looking great. If you do want to start doing something about it these jobs will have the biggest impact.
Fix your roof
When there is nothing wrong with your roof it's impossible for anyone to pay particular attention to it, unless they're judging you on how much moss there is. When you have holes everywhere it's a different story and it looks horrible. If you do have missing or cracked tiles it also means there is a chance of water getting in, so not only does your roof look a mess but you have to spend thousands getting the ceiling fixed when it eventually collapses.
Paint your home
There will come a time when the outside of your home has been attacked by the elements for too long and it will start to look worn. The paint will fade and the house will age 50 years. You can combat this by rolling up your sleeves and giving the place a good paint. If you don't want to do it yourself I'm sure you can find someone who will do it for a considerable price. The paint won't cost much and your home will look a lot better.
Check your fence
When it's windy enough your fence will get knocked about the place and after so many years it might start falling away. Big holes or missing planks on your fence can be fixed in about 30 minutes and you only need a hammer and nails. You could even take some of that paint you have left and give it a nice fresh coat. Just remember that you can go to the store and buy a paint gun which will shave hours of the time it will take you to do it.
Cut your hedges
You will be surprised by how different your hedge looks when it's been trimmed. Most people don't seem to touch it and they wonder why it looks a mess. Get your shears out and spend a day working your magic on it. If you want to know how it's done just imagine giving someone a haircut. Once it's finished you can pick up all the crap and take it to the dump, unless you have enough room to burn it.
Throw away the crap
There will probably be old stuff you keep in your garden just because it's there. Maybe it's too hard to throw out, but if you never get around to it your garden will never look great. The easiest way to do it is by forcing yourself to go outside and deal with the problem items before more years pass. You might even want to go shopping to buy some new garden furniture now that much more room has become available.