Know the relationship between word length and the numberof strikes your oppontent gets, and use it to your advantage. For example, when constructing a four-letter word, do a mental check that there are enough words with similar letters to make the word last eight attempts. You can be less diligent when creating longer words, but do try to swap out some tiles to change the word to a less common one where possible. Here's how many strikes you or your opponents will receive based on word length (four letters is the minimum you can play).
When it's your turn to create a word for your buddy to solve, follow these tips. Use the most uncommon letters in your pool. Ever watch Wheel of Fortune? The most common letters are R, S, T, L, N, E. People will guess these letters. Try to use letters they won't guess, like X, Q and X. Don't use the same letter twice. If you use the same letter twice, you'll help the other player by giving him two letters for just one guess. Words are much harder to figure out if they don't have repeating letters. Use an online anagram generator. This is a bit cheesy, and you can tell your friend to blame us. But search for online anagram generators and type in your pool of letters to get a bunch of words that your letters can spell.
Use your Lifelines Wisely
Lifelines can give you a leg up when trying to solve some of the trickier words your opponents play. For example, if you know the word ending but there are a multitude of words or starting letters that apply, you can use "Suspects" to quickly narrow down the selection and display four letters, one of which is in the word. Make sure to keep a mental note of the letters in case you guess wrong. Generally, it's a good idea to be stingy with your lifelines and only use them when your opponent has a big lead over you or if you're down to your last balloon. To build up good supply of lifelines, make sure to leverage score modifiers when constructing your own words whenever you can. Tryto start off by placing the highest-value letter on a DL or TL field and work from there. And if you're short of a TW or DL field, think about how you can extend the word, by making it plural, past tense, converting it to a noun, or similar.