When we move we're likely to have a much smaller garden - and no doubt I won't be able to commandeer all of it for vegetables, so 'Timely Tips for Small Garden'found recently in a newspaper,may well be very useful:
1. Grow Potatoes in pots - we're trying that this year - three sacks in the back garden - and will report back.
2. Grow Squash not Pumpkins - or how about courgettes? Perhaps try growing them vertically? Or even remember to only plant the number of plants actually required rather than the whole packet!?
3. Grow vertically using wigwams - Cucumbers,  Beans. Would any other fruit/veg work with this?
4. Buy plug plants if you don’t have a greenhouse - or bring on seeds on a warm windowsill in the house. Again, plug plants are useful to make sure we don't grow too much of anything, it's just so easy to sow the whole of the packet!
5. Build and use a coldframe - yes, and must remember to open it in the daytime to avoid 'damping off'.
6. Use every scrap of soil you have by planting closer than the book suggest (but remember to use a general purpose fertiliser) - make own compost?  Ask local hotels/residential homes for their spare veg peelings?  Buy a wormery?
7. Plant in rows north to south to minimise over-shadowing - good idea, haven't yet tried this.
8. Train fruit onto walls or along wires - espaliers, cordons.
9. Only grow what you like to eat - and things which are expensive for supermarkets to transport, such as raspberries and spinach.
10. Use hanging baskets for plants such as cherry tomatoes - will try other veg/fruit too . . . such as strawberries, lettuce, peppers? Also nasturtiums as they love to trail and the flowers and leaves are yummy.

http://www.mytinyplot.co.uk/