The more you worry about an issue such as cornering the worse it gets, until the only thing going in tighter and tighter circles is your decreasing confidence. The good news is that becoming a far more confident bike handler is very quick, and surprisingly easy if you dedicate some specific time to it. You can also fit the sessions around your normal training for an ultra time-efficient double whammy.
The first step is to find a good, traffic-free place to practise. Empty car parks are great, especially multi-storey ones, which will be pretty dry, whatever the weather. If you’ve got a mountain bike (or can borrow one) then a soft grassy playing field gives a comfier crash surface for pushing your limits.
A training partner – either another rider or just someone who can come and watch what you’re doing and add coaching/encouragement – is a big bonus too. If it helps your confidence, wear a thick jacket and jeans, or even mountain bike style pads.
Now, make a short lap that you can do over and over again by riding round a couple of fixed points (water bottle, jacket, traffic cone, whatever is handy). At first, just lap slowly so you don’t have to brake and concentrate on relaxing and letting the bike roll round smoothly.
Press your weight onto the outside foot, point your inside knee into the turn, and learn to drop your inside shoulder too. Your bike will always go where you look, so concentrate on the correct route, not what you’re worried about crashing into.
As you come into the corner, stare at the turning point (apex). Once you’re passed that then immediately flick your vision as far past the exit as possible, and your bike will follow. Try a few laps in one direction, then turn round the other way to make sure your cornering is balanced and you’re not getting dizzy.
Now try riding hard out of corners and then braking firmly as you come into them. Never brake as you’re actually turning, as that reduces body relaxation and increases the chance of skidding. As your confidence in how fast you can go round increases, you can start to play about too.
Try going into corners wide and exiting wide, going in wide and exiting tight, going in tight and coming out tight and so on. See what difference that makes to your overall speed and workload around the lap.
Soon you’ll be flying round the lap, braking hard then swooping round like you never thought you could, before powering out the far side. At this point start to add variety such as a slalom run where you have to flick the bike from one side to the other.
Downhill and uphill corners mean you need to rethink your entry speed as you’ll accelerate or decelerate through the corner, which can be spooky at first. Devote some time to cornering confidence and you’ll be astonished how quickly you improve.