HI Bex, sorry to hear your ankle is playing up again. There is certainley plenty you can do to help improve your proprioception (the ability of the ankle to know where it is in relation to the rest of the body) as this will improve balance reactions and thus prepare you better for walking on uneven surfaces.
Start of by going back to basics and practice balancing on 1 leg. As you improve and feel steadier, gently raise up onto the toes and lower down slowly. Repeat this action making sure you minimise the wobble! Once you have improved your balance in a static environment, you need to challenge it by adding more movement. Get comfortable with side stepping and walking backwards, and then gradually increase your speed into a jog concentrating on how your foot lands on the ground. Try moving in a figure of 8 and practice changing direction more quickly. All of these directional changes help to stimulate some of the dormant receptors in the ankle ligament thus improving your ability to react to change, which is essentially what your ankle has to do when you walk on uneven surfaces. The better the ligaments are at detecting change in direction and stretch, the quicker they send messages to the muscles to contract and protect the joint. Remember, progress slowly and make sure you spend enough time doing the static balancing before you progress on. You should be able to stand easily on the bad leg alone for 1 minute without a wobble!! Good luck, let me know how you go(If you have access to a wobble board or similar device then that would be even better).
Sarah Carter (Physio)