To practice spelling, study a small portion of the spelling list at the time by either creating flash cards, or writing the vocabulary words down correctly multiple times. Ultimately, learning spelling words takes repetition and correction until the vocabulary word sticks. Have someone create a mock quiz setting and test yourself. Check and correct the words if necessary, then repeat. Make sure to quiz yourself on the words you already know to ensure they stick.
Spelling is a vital component in every language, especially when it comes to reading and communication. Specialists, such as Susan Jones, M.Ed., have published research showing how spelling improves reading and writing, vocabulary and comprehension. This has been questioned with the introduction of modern spell checking technology, however there is currently no argument that can completely overturn the importance of spelling.
At its core, spelling is used to help an individual learn to read. A reader gains fluency over the written word, and can learn high-frequency "sight words" to improve his mastery in both reading and writing by understanding the letters and sounds and how the combinations work together. By doing this, the reader gains access and exposure to new vocabulary and ideas, which can then be shared and built upon when communicated with peers.