These Sound mats are a good reference tool to have in front of your child when they are writing, and can also be used for practising grapheme sound recognition.
 
Each mat has single letters, digraphs or trigraphs with accompanying pictures.
 
They follow the order of a very common scheme called 'Letters and Sounds' and are organisind into the phases from this scheme.
 
My free 'beat the teacher' style recap videos on YouTube also follow this order and are a good reference tool if you are unsure how to pronounce any of the phonemes.