Though standard peach trees like yearly pruning to encourage flower-bud formation, almost every bud on the new growth of miniature trees is a flower one. So they don't need pruning to stimulate production.
Miniature figs are extra useful because they have lovely big leaves and a spreading habit, so you can plant them to shade you while you're sitting down to admire the rest of your miniature orchard. To make sure you get a fig that stays diminutive, choose a grafted plant. It will provide support, help the tree grow faster and speed up the time it takes to fruit. Miniature olives are also gorgeous with their delicate silver foliage. Unless you're prepared to process the olives, you might be best to regard these as decorative rather than productive though.
When winter rolls around, plant ballerina and crab apples and bonanza peaches. They have beautiful blossoms in spring and fantastic fruit in summer.
Cherry guavas and unique feijoas are also self-pollinating and easy to grow.
The unique feijoa, a self-fertile cultivar from New Zealand, is a small, productive, vigorous tree growing to about 2.5m - great for smaller gardens. And, like many small, vigorous things, it's efficient at what it does, so don't be surprised to get more than 30 fruit in the first year. Most miniature trees are self-pollinating, but grow several trees together to encourage cross-pollination and you'll get even more fruit.
I grew a gorgeous miniature kiwifruit vine a few years ago (unfortunately, all our cats were seriously attracted to it and eventually loved it to death) and it provided the cutest little kiwifruit you've ever seen. So I was just a bit disappointed to discover that most minis provide regular fruit, and plenty of it. So no need to buy a smaller fruit bowl - in fact a larger one is probably the way to go.
Don't despair - espalier!
If your garden is even more miniature than the most miniature of fruit trees, don't despair. You can espalier them.
Espalier means a central stem with horizontal arms tied along supporting wires, and because the tree can be kept virtually flat, it doesn't encroach on precious outdoor living space.
You can espalier fruit trees by stringing wires horizontally along a wall or fence 60cm apart, or training the growth into a candelabra or fan shape. If you don't have a wall, a free-standing frame strung with wires will do the trick. Set your posts about 4m apart with 2m above ground and string five or six wires tightly between them.
Almost any variety of apple or pear is suitable to espalier. As with traditional plants, espaliered fruit trees require a sunny, sheltered site with good air circulation. Be careful, though, before you go down this path - it can become addictive. Before you know it, you'll be surrounded by wires and talking of nothing but oblique cordons, candelabra and Belgian fence designs.