ME
Get a credit card and pay the insurance off in one go with that. Sometimes it can chop off as much as 25% from your premium.
How old are you?
How long have you been driving?
How many years NCB?
Which postcode grade do you live in?
http://www.carinsuranceexplained.com/car-insurance-explained/car-insurance-postcode-risk-list.html
Do you have any points/convictions?
Try adding your mum to the policy as a named driver, see if that changes it at all.
Run through these sites..
moneysupermarket
comparethemarket
confused
elephant
admiral
bell
directline
aviva
post office
tesco
Also, check this site for
tweaking your job title for the cheapest quotes
http://www.moneysavingexpert.com/insurance/car-insurance-job-picker/
It'll take about 20 minutes if you hammer through them.
I highly recommend creating a new email address to do this! (to stop spam) and use a fake phone number. If you take out a quote, update your email&phone number when confirming the details
I find Admiral give the best quotes for me.
Avoid places like Swift cover unless you absolutely have to, they don't have proper windscreen cover etc.