When buying an engagement ring with your boyfriend, take him to a really expensive shop first, then he’ll think the next place is a bargain.

If you have a good feeling in your tummy that a proposal is imminent, make sure you have a little chat with your best friends and family (especially your mum!) and let them know roughly what your tastes are and what you dislike. They'll also know your ring size this way. You can be guaranteed that your other half will ask one of them about ideas for a ring, and they can be subtly helpful without ruining his moment when he proposes. Perhaps they could even help him out by going to the jewellers with him? (remember Samantha choosing Carrie's ring, from "Sex in The City"?)

Use online jewelry shops to browse for styles you like--then you can show your significant other the types of things you like. That allows them to deal with the hassel of finding a ring they can afford without having to worry about whether you will like it or not as well. Its also good to know your ring size--taken by a jeweler (sometimes the costume jewelry size is not accurate to your true size) and share it non-chalantly with your partner.

If you're going with your boyfriend ask him to wear a white dress shirt. Hold the stone of diamond rings against the cuff when the jeweler offers you his loop, you'll see the inclusions better this way. Also, work your search engine, there is a web-site that sell engagement and wedding set from couples who have broken up. Remember a guy can only get about 1/3 back if he tries to return the ring if the woman says "no!", so you might be able to find a bargain.

Always go to a wholesaler shop, I use to work in one called Bond, which not only sell limited and unique pieces at great prices, but sometimes designs and make there own, each individual jeweller will always go to a jewel sale, the man who runs Bond, always went to Bangkok where they hold huge diamond sales, with unqiue pieces of jewellery, its heavily armed with guns men etc. Basically it cuts out middle man sellers, places like H.Samuel often buy from other people, what buy from others, and the diamond, and ring is not worth its money plus everyone will have similar on. If you go to a wholesaler, and say i want silver/gold band with a black diamond, he will either design, make or find you one, unique, and one of a kind.

I would recommend trying a manufacturer first, we had our wedding rings made to match my engagement ring and the weight and quality of gold far outmatches anything we'd looked at in jewellers and they are special to us. I would advise you to avoid white gold as it is rhodium plated (white gold is dull and grey) and it wears off so you have to have it re-plated at a fair cost - jewellers don't tell you that!