Speaking only from a Spanish stand point, there is a fast and easy way to help students prepare to go to school if they only have a few minutes to spare each day. Flash cards always helped me with all my subjects throughout my undergraduate years but especially with Spanish. Buy some note cards and write down the tenses you are struggling with and some examples. You could even write some vocab words or create a table with each conjugation and tense. Punch a hole in the corner of each note card and place them on a ring. This is the longest part. Once you have this done, flip through the ring a couple minutes a day. With any language, repetition is key!