Someone more knowledgeable than me can correct me if they know different but someone told me they see the colour yellow the best . When I first started trapping I used to sprinkle the maize around and he told me it's better to leave it in a little lump. They're more likely to see it and come searching.
Now if that is correct I was thinking of getting some thin ply and painting it bright yellow and putting it by the front of the trap with a little maize on . Hoping that they see the big blob on yellow and come looking . Maybe on a feeder a nice dollop of yellow paint splodge might entice them down quicker and in more numbers to see what's there
Or if it's all bollocks I've been told then just peanut butter ,maize and peanuts are what I try bring them in with traps