Two months' salary is a generalization, so try for a ring you can comfortably afford. One tip: several smaller diamonds produce big sparkle, with less cost.
Diamonds are the most popular choice for engagement rings, but many brides-to-be have other preferences & likes. Sapphires & rubies are two other popular stones.
Precious metal options include platinum, gold, silver and tungsten. Make sure you know what your partner prefers to ensure you get the perfect ring.
Consider the carat weight & gemstone shape as they are important to the overall look of the ring. For instance, slender hands should have a smaller ring.