Hello MxJayne and Welcome to the Forums! If you're using the touchscreen to try to place the items, you could try using a mouse for only these things. Many people on phones and tablets have mentioned touch problems with trying to access small areas of 1 tile only and your issue sounds similar. The fix for mobile is they can pinch to expand to make things real big on their screen to access the spot quickly and then shrink it back down after they grab the thing or access the spot.
You could change your screen zoom in the preferences if you're away from a mouse or if a mouse is convenient, try using that.