Keep making leafmould
Rake up leaves to make quality leafmould – even a small garden will shed enough to stuff a sack. Don’t worry if the leaves are a bit wet as the moisture encourages the fungal moulds needed for decomposition. When the sack is full, tie the top securely then use a knife to make a few slits in the bag to allow some air to get into the process.
Store the bag somewhere in the garden. It will take a year or two before you have the perfect soil improver but it is so worth the wait.