To take useful photos it will take two people.
The first person needs to take the photo. They need to ensure that the photo is focused and metered on the area underneath your child's tongue, if using a smartphone this can usually be achieved by touching the screen in the area underneath the tongue. It is also important to ensure the flash is set to on. It is sometimes easier to take a video and then either select frames from this or send a short video.
The second person needs to get both index fingers underneath your baby's tongue right back to the base of the tongue. Then they need to lift the tongue up as high as possible whilst holding your baby's chin down with both middle fingers, this will put tension in any tongue frenulum that is present and thus give us the best view of how much it may restrict elevation.
To get a good photo of the lip is much easier. You just need to lift the lip as far as you can to the nostrils by holding the upper lip between both index fingers and thumbs. This is often easier when your baby is asleep.
If you attach these to an email in the best quality possible.