If you've returned home from holiday to find all your lettuces a foot tall and bitter, there's still time to sow another crop. Just remember that lettuce seeds don't germinate if it's too hot, so keep the seed trays in cool shade.
Or be easy on yourself and buy seedlings. At this time I find the non-hearting types such as mignonette or Yates Frilly Mix seeds easy to grow.
Sow coriander, radishes, spring onions, spinach, baby beets and mesclun all in the same area so watering and picking will be simple.
Those old bedraggled lettuces often have some good leaves left, or a crisp heart. Use these to wrap around prawns and serve with a fish and rice wine vinegar sauce with ginger and chillies, or wrap those leaves around tiny cheese balls and serve with a tomato dipping sauce.
Don't sow Chinese cabbages now as they will grow too fast and set seed. Wait until autumn to sow them.
If your courgettes and cucumbers have invaded other parts of the garden, pinch the tips off when there are at least six big leaves. This will encourage the fruiting branches and keep the plants within bounds.