One way to get better at spelling is to remember the spelling rule that the letter "i" comes before "e," except after "c," or when sounded like "ay," as in "neighbor" or "weigh." That rule will help when confronted with how to accurately spell a word like "relief"; the rule makes clear the order of the letters.
Devise a memory aid to help with words that are especially problematic. For example, "desert" and "dessert" can be problematic when it comes to figuring out which one means an after-dinner snack and which one is a place. Since everyone wants seconds of the after-dinner snack, it makes it easier to remember the correct spelling as having more than one "s": "dessert."
Another mnemonic, or memory device, can help with the often confused words "stationery" and "stationary." One of the words means papers with matching envelopes, and the other means standing still. The word "envelope" starts with the letter "e," making it easy to remember it is part of "stationery."
Make an effort to always pronounce words correctly. This way it becomes easier to hear how each syllable sounds and which letters make up that syllable. For example, properly enunciating "library" will prevent the misfortune of spelling it as "libary" or another variant.