Feeling a little fuzzy about what went on during the summer? Keeping a daily diary will not only help you remember, it'll also give you a chance to practice summer-related Spanish vocabulary. Don't worry, you don't have to keep the diary only in Spanish unless you want to (although this is one of the quickest ways to improve). But the more Spanish words and phrases you sprinkle through your diary--think subheadings, titles, or even just the occasional vocabulary word to stay in practice and make yourself feel cool--the more your Spanish summer practice is worth. Those words will stick with you and be readily available when you're up in front of the class trying to express what you did in Spanish.
Take it a step further: If you're a fan of the last-minute cram, you can prep for your first few Spanish classes by translating your English-language diary into Spanish. For every word you come across and don't know how to translate, make a flash card with either a picture or the English-language translation on one side and the Spanish word on the other. Study. Repeat.