Find the common two and three letter words first. Do the columns with all the same letters if there are any.
Keep going until you have found all the little words. REMEMBER - each letter is used ONLY once.
As you use a letter CROSS it out so you don't use it twice. Each column has the exact number of letters for that column - don't mix columns.
After all the small words are filled in then it becomes a process of elimination and deduction. REMEMBER - some of the words wrap around to the next line.