To win the word guess game consistently, open with a five-letter word full of common letters, use your next guess to test letters you have not tried yet, and build every guess after that around the greens and golds you have collected. The colours carry the information; your job is to use all of it. You can try the method on the live Word Guess game.
Start with a strong opener
Your first guess gives you nothing back until you submit it, so make it work hard. Pick a real five-letter word with as many common letters as you can fit, aiming for three different vowels and a couple of frequent consonants. A word like that tests a wide slice of the alphabet at once, and whatever comes back, greens, golds or greys, it eliminates or locates a lot of letters in a single move.
Avoid opening with repeated letters or rare ones. A word with two of the same letter wastes a slot, and an unusual letter is unlikely to appear.
Read every colour
After each guess, the letters change colour. Green means right letter, right place, so lock it in. Gold means the letter is in the word but somewhere else, so keep it and try a new position. Grey means the letter is not in the word, so drop it for good.
The most common mistake is ignoring the golds. A gold letter is a confirmed part of the answer; you just have not found its slot yet. Carry it forward every guess until it turns green.
Spend a guess on information
When you have a few greens but cannot see the answer, you do not have to guess words that could win. Sometimes the smartest move is a guess that tests five letters you have not tried, even though it cannot be the answer, just to see which ones light up. One guess traded for that much information usually reveals the word faster than guessing in the dark.
There is a fresh word every round, so you can practise the method as often as you like, and your best result by fewest guesses is saved on your device. Open the Word Guess game and try a strong opener, and for why word puzzles are good for you, see the benefits of puzzle games.