I will try my best to explain how you can reach a concept that will take the shape of a functional and charming logo. You must understand I won't tell you how to design logos like mine since that's impossible unless you are trying to copy them and next you will see why.
Please forgive me if I lost track of my ideas, it will be a bit difficult to explain something that has become natural to me after years of practice.
What's an idea and what's a concept
If we look for it in a dictionary, an idea is something as simple as a thought, a mental image, a word, an opinion; while a concept is a plan, an unified idea, a philosophy.
From my personal perspective as logo designer (try to image this), an idea is a lightbulb and a concept is a chandelier with many lightbulbs. Now let's try making a more complex concept. Let's say inside each lightbulb of the chandelier is a letter and together they spell "classic". If you make that into an image you have a logo, more or less.