Establishing broad outlines is a good start. But your design is shaped just as much by lots of small decisions. Here are four examples.
How high do you like your capitals? The proportion between capitals and lower case makes a big difference to the look of a typeface. In the second example from the left the proportion is the same as in Times Roman.
The letter r on the left has a small ear. The letter r on the right has a large one. How big do you want yours?
A small ear makes spacing easier, but it can look insignificant. I think the second letter from the left is nicely balanced. But thats my choice. Yours may well be different and just as good.
The waist of these letters is each of different height. The top and bottom counters need not always be balanced: a low waist can look fine in an unusual character set.
Knowing how to balance the counters, as in the middle letter, is a convenient skill. You blend a few variants between a high and low waist and use the best result as a your starting point.
What makes a proper letter g? All of the above. For ordinary reading, the proportions of the letter in the middle are popular. But it is one of many solutions. What is the purpose of your design?
The letter on the left has a large upper bowl. It would look right in small size, among letters with short ascenders and descenders. The bottom bowl of the rightmost letter is no larger than in serveral fine and graceful designs.
One of the troubles in designing type is working out in detail what you want. The best way I know is to make tests, plenty of them.