1. Be familiar with the terms that you'll be confronted with when shopping for a ring. Giving the impression that you know what you're looking for will increase your confidence and help you to ward off any disreputable ring sellers.
2. Choose a good jeweler. The main thing to remember here is that expensive doesn't necessarily equate with being the ideal jeweler. Look for a store that makes you feel comfortable, where the staff are pleasant and helpful, and where the advice they provide gels with you. As well, be sure to look somewhere that fits within your budget range; this avoids the inevitable disappointment at finding something that would be "just perfect if it didn't cost so much". If you can, check that the jeweler is registered with a society, association, or organization that regulates, certifies, etc., jewelers, such as the National Association of Goldsmiths in the UK
3. Find out her tastes. If you're purchasing the ring without her, choosing one will be will more difficult where the ring is a surprise because obviously you won't be able to ask her. Do keep in mind that nowadays, many women prefer to be part of a joint decision to purchase a ring, so if you find it really difficult to know her style and taste, provide a temporary ring and tell her that you'll choose the real one together.
4. Fix your budget. There is a tradition that holds that a man should spend two months of his salary on the engagement ring. Whether or not you do this will depend on your wish to conform to tradition. What does matter is that you select a ring according to what you can afford, so have a good idea of this amount before searching.
5. Check the practicality of the ring.
If your girlfriend is a real outdoorsy type, consider a ring that is able to cope with the wear and tear of constant activities. The higher the positioning of the gemstone on the ring, the easier it is for it to get caught on clothes, gear, hair, etc. and the greater likelihood that it'll get knocked about. Look for a lower gemstone setting for an active girl, and a higher setting for a fashionista or glamor girl.
6. Check durability. The durability of the band is important, as constant rubbing and knocking from daily activities will eventually wear down the band. And office work is a killer, with paper acting as a mild abrasive on gold bands. If you can afford it, platinum is the preferred choice for wedding bands as it is more durable than gold, Titanium and steel are also fairly resistant, while the purer the gold, the softer it is and more prone to wearing.
7. Know your diamonds. Diamonds tend to be the traditional engagement ring choice, because they are enduring, and match everything. Only deviate from a diamond if you know that your girlfriend loves another stone much, much more, or has voiced her intense dislike of diamonds.
8. Decide by how it looks.
Once you've covered the cost, the durability and the practicality of the ring, it's down to how the ring looks.
9. Purchase the ring. Collect it just before the proposal. That way you can avoid worrying about keeping it safely.(wikihow.com)
