1. Use a thinner pick. A thinner pick will help you to more easily control the string and avoid pushing down on multiple strings at once.
2. Try using a different fingering technique. There are different ways to finger chords and melodies, and some of these techniques may work better for you than others. Experiment until you find a fingering that allows your fingers to stay relaxed and avoid pushing down on multiple strings.
3. Practice regularly and strengthen your fingers. The more you play the guitar, the stronger your fingers will become, which will make it easier to control the strings. You can also do specific finger exercises to help strengthen your fingers and increase your dexterity.
4. Try using a guitar with a wider neck. A guitar with a wider neck will give you more room to move your fingers and avoid pushing down on multiple strings at once.
5. Consider getting your guitar professionally set up. A guitar that is properly set up will make it easier to play, and it may help to reduce the chance of pushing down on multiple strings at once.