Also, every sequence of five or six letters most always contains a vowel. Look for doubled letters. The most often used doubles are L, E, S, O and T. Check the final letters of the cipher's words. With these helpful hints you are well on your way to solving most cryptograms that are published today. There is a myriad of encryption methods, and once you have the method or system you can fairly easily unlock the key.
Intuition is the strongest factor in gaining insight to a key.
Allow your subconscious to scan the ciphered text and quietly wait for some subtle feelings of how to proceed. Once you've discovered the key or some important words, logical thought takes over and you proceed to unravel the algorithm that was used to encrypt the message. This is another fun way to use both sides of the brain. The Internet is full of sites that have cryptograms. As you play with this you may become interested in the science of cryptography itself.