As a nurseryman I spend a lot of time getting plants to do what I want when I want them to and in a space that I dream about being double the size. So many people are in the same position as me, the basic difference being it's home and not work.
You want it to look beautiful or neat, or both, and with so much emphasis put on 'grow your own' there is also the expectation that it should produce wonderful veg and flowers. These expectations are the same with me and although the approach is different the basic concepts are the same.
If you have a limited garden space make sure you use your walls and fences productively. Espaliers, Fans and Cordons are a brilliant way to get a massive volume of fruit whilst using very little of your garden's precious floor space. This is especially important if you have kids or dogs as they will only congratulate you by pruning with a football or finding the tree as appealing as a lampost for peeing against. (I point out here that the children prune and the dog pees just in case there is any misunderstanding).
Pruning is once a year on trained fruit and it is, to me, one of the most relaxing passtimes you could have. Be mindful that the range of fruit found ready trained is more limited than that of bush fruit but if you are brave you can take a maiden (term for 1 year old grafts not Guinevere) and turn it into whatever shape you like if time doesn't worry you. Make sure that your rootstock is correct and the variety is spur bearing not tip bearing.
These all seem like strange terms if you aren't used to them but a quick google search or visit to a garden centre or nursery with knowledgeable staff will have all of these questions answered usually with a trained fruit tree in front of you so it all makes sense on a practical level. If you decide to visit the nursery ask for myself or David and we will happily explain as little or as much as you feel you would like to know.
It is worth knowing what fruit will suit which style of train so I have listed them below:
Stone fruit (Peach, Nectarine, Plum, Damson, Cherries)
There are other ways in which to save space when producing fruit. The obvious is to use a cordon or minarette tree to form a column of fruit in a border or parterre but remember that ripe colouful fruit requires a good aount of sunlight so don't grow things through them or right up the stems.
The second way is to use stepover fruit as a border to beds and veg plots. Stepovers are effectively the first tier of a an espalier designed to show the border off but demarking a boundary at the same time.
There is a lot to explore with trained fruit, including u-cordons and candelabra trains. As always remember that a garden is trial and error and should predominantly be a pleasure to undertake. Yes there is some hard work but the effort will reap rewards, especially with fruit.