Convention dictates that a ring, most popularly diamond, should mark an engagement. Other stones, such as sapphires and rubies, may also chosen or used as side-settings.
It is not necessary to present an engagement ring when proposing; many people decide not to choose the ring alone. A safer option is to give a piece of jewellery - such as a bracelet - that the groom knows his fiancée will like.
However, the ring should be on her finger within a reasonable time - weeks, not months.
It is still customary for the groom to pay for the ring; he should get the very best he can afford.
Consider the bride's taste, her hand shape and her realistic expectations.
The groom may wish to select a few rings for his fiancée to choose from, or the couple may decide to look together.
A family heirloom or antique - either a ring or a set of stones - may be can be cleaned, adapted or re-set.
If the couple choose the ring together, a budget should be established in advance.
Several styles should be tried; it is advisable to experiment with a range of cuts, sizes and settings.
Trying the engagement ring on with a wedding band - it will look different alongside another ring, rather than on a plain finger.
Popular metals for engagement rings are: white gold, gold and platinum. The metal of a wedding band must match the metal of the engagement ring.
Trusted or recommended jewellers should be used; listen carefully to their advice.
Retailers will be happy to advise on the quality of stones. A diamond is valued using the 'Four Cs': carat, clarity, colour and cut.
Insuring the rings
Both the wedding rings and the engagement ring represent a major outlay, and therefore must be insured - the latter to the full value of the stone or stones. Jewellers' receipts should be kept in a safe place in case a claim has to be made.
Many brides-to-be like to give a substantial present to their fiancé as a way of marking the significance of the occasion. Popular choices include a watch, cufflinks, or a beautiful pen.