Buy your rings in the sales so you can afford to buy something a bit more expensive but within your price range.
www.warrenjames.co.uk/jewellery/certificated-diamond-rings
Start selling your old or unwanted stuff on e-bay/car boots sales that you do not need anymore to generate extra cash to supplement your small budget.
for eg. I recently sold some gold bracelets that I inherited for 2k. If you set your mind to it it is amazing how much you can raise.
Open a high interest, fixed term notice account where you can save specifically for your wedding.
Cancel Christmas gift s this year, just buy small token presents if need be.
Cancel your annual holidays.
Cancel hobbies/subscriptions for a year
Have a late afternoon ceremony (4/5pm) so you can invite everybody to the wedding ceremony & reception afterwards. That way you have one set of catering costs so you can feed everyone. My friend did this & avoided paying an additional 2k for a buffet.
www.moneysavingexpert.com/banking/Budget-planning
This is a good site to help you budget for the wedding
Sign upto costco or a cash & carry so you can buy big catering multipacks of food & drink for a fraction of the price of going tobuy it from the supermarket
warehouses.costco.co.uk/membership/
Get married on a weekday as there are always good deals around. It is also a good way to manage your guestlist so only those closest will go to the trouble of taking leave for a mid week wedding.