There are so many ways to hold a plectrum and strum the guitar. It's also simple to fall into bad habits. Something I have been guilty of in the past when playing the guitar is holding my plectrum a little further away from the strings than I should. The downside of this is speed issues and getting to the next note on time and merely giving myself more work to do.
The positioning of fingers on the fretboard is necessary as well. Through the years I have had to address my pinky sticking out while playing chords.
I'm glad to say there are so many exercises out there that are helpful in addressing these challenges. A top tip is to video yourself playing and see what you can pick up, then just practice the new techniques to eradicate any bad habits.
Oer the years I have noticed a great improvment in my playing due to addressing these challenges however its important to always look out for these small things.
Good times when guitars are around.