Start by shredding or chopping your cooked chicken into bite-sized pieces so every scoop gets a good mix of textures. Dice the avocado into small cubes rather than mashing it, since you want soft chunks throughout the salad, not a paste. Set both aside in your mixing bowl while you prepare the rest.
In a small bowl, whisk together the mayo, Greek yogurt, lime juice, garlic powder, salt, and pepper until smooth. This creamy base is what carries all the flavor through the salad, so take a moment to taste it before moving on. Adjust the salt or lime here if you want, since it's easier to fix now than later.
Pour the creamy mixture over the shredded chicken and diced avocado in your large bowl. Add the chopped fresh cilantro at this point too, since folding it in early distributes the flavor more evenly. Gently fold everything together with a spatula, being careful not to mash the avocado chunks.
Cover the bowl and refrigerate the salad for at least 20 to 30 minutes before serving. This resting time lets the garlic, lime, and cilantro really soak into the chicken instead of just sitting on top. I've tried skipping this step before, and it truly does taste better once it's had time to chill.
Once it's chilled, give the salad a final taste and adjust the seasoning if needed. Sometimes I add an extra squeeze of lime or a pinch more salt depending on how ripe the avocado turned out. This is also the moment to decide if you want to fold in any extra add-ins like celery or onion.