Ovulation strip tests

So I’m new to the whole ovulation strip tests, I’ve completed one every morning but can never seem to get a dark positive line (They always seem light or not dark enough!)

I’ve seen many posts on using the strip tests and many people have given different advice about using them.

I was just wondering, when the best time is to do a test? Would the line be darker at another point in the day or do I just go off a morning reading?