get students thinking about the vowel sound before they start spelling
If you have a student who struggles with selecting the correct short vowel when spelling, one technique that might help is to use a different color marker for each vowel.
You’ll need your drill cards with the short vowel on them, and 5 different color markers. Set the vowel cards out on the table, and have the student place a different color marker on each card.
Have your student commit to choosing the vowel sound up front, before they even get started sounding out the word on their fingers, by having them pick up a marker. You want them to work out which marker to pick up after they’ve repeated the spelling word back to you, but BEFORE they start finger spelling it. This reinforces listening for the vowel sound, and allows you to correct and provide help up front instead of waiting until they’re already in the middle of spelling the word. When they’re ready to write the word on paper, they can write it using the colored marker they are holding.