You don't need a huge bag to make compost and it doesn't smell (generally). Compost bags are normally ignored by all the common pests such as rats and foxes and they take very little work if done correctly.

We use the 1 ton "skip bags" that you can get from B&Q but you can often pick up for free from people having building work done. They last for ages (ours are 3 years old and still good as new). If you don't have enough space for a bag this big a smaller one (the size of the green bag) will also work. If you don't want to use a bag then a bin with the bottom cut out and sat on the ground will also work.

We throw all our uncooked vegetable matter in our bag as well as grass cuttings, small twigs, bits of plant and the million or so leaves we get each year. Leaves compost slowly so it takes about 2 years to make good compost but a compost heap made from grass, small twigs and vegetable matter can be done in as little as 6 weeks.

Cooked vegetables generally shouldn't be composted. For some reason they don't work very well and can cause smells. Also, you shouldn't put in meat (that will attract rats and foxes) or paper. Some paper can be composted but it's hard to get right. Tea bags generally work but they are more hassle than they are worth as they have to be broken up.

The secret to generating compost is air and water. Watering your compost heap in the summer will really help make compost - the bugs making the compost need to drink. Air is harder and can only really be added by turning the heap which is a heavy job. I generally only turn ours once or twice a year.

You need to cover the top of the heap with something. We use a bit of old underlay but carpet or poly sheet will also do. It helps stop water loss from the heap.

Site the heap away from the house if possible (end of the garden is good). Fresh vegetable matter tends to attract fruit flies for a couple of weeks. There's not much you can do about them and they are actually beneficial in breaking down the vegetable matter. It's only a problem in the height of summer.