The following idea has worked well for several of my Special Needs Pupils in Y3:

Do you have older pupils who continue to have problems remembering the letters they need when writing? Make an individualised alphabet 'frieze' using a wordprocessing program like Textease or Word.

The child chooses a word to match each letter of the alphabet and chooses a piece of clip-art/photo/graphic to illustrate it. The resulting alphabet card can be printed out and laminated, then used with every writing activity. I've found the involvement of the children in making their own really helps them remember and they find the letter they need much quicker than with any wall-based, published examples.

This can easily be extended to support work on sounds, numbers or colours and concepts.