A few thoughts to get the discussion started:
Maintenance Grants and Loans rarely cover all of your year's living expenses. There's still an expectation from Student Finance that parents will help, although many households' outgoings are so high these days, that it's the exception rather than the rule.
Accommodation - both private and uni-run - can ask for a deposit and a month's rent in advance. This will usually be due before your loan/grant arrives, so you need to arrive at uni with funds available for that.
Your loans/grants don't arrive until after you start uni - sometimes a week or two into term (there are a number of processes which can delay its arrival in your bank account). It's always useful to have money to cover at least food and drink for a couple of weeks.
Make sure that you apply for Student Finance as early as possible, and be very careful to give the correct information and provide the correct documentation. If you get anything wrong or miss the deadline, your payment can be delayed for weeks or months after the start of your course.
If possible, I'd advise saving as much as possible in advance and planning to get part-time work once at uni. It's better to have money that you don't need, than to need money you don't have.
Your savings won't impact your entitlement to Student Finance. They only take income into account, which would effectively be the interest on those savings. With interest rates as low as they currently are, that's unlikely to impact your SF entitlement.
Have a look through the posts in this section, to see some of the problems that people have encountered. That will give you ideas on how you can avoid the numerous potential pitfalls.