As a Graphic/UI/UX designer. We must maintain our typography concept. Because typography is the main element of design. A famous man said, “Typography is an art”. In fact, if you don’t have any design concept or any idea you can use these rules and you will be impressed.
Let’s start beginning.
Rules Number #1:
PREMIUM Line Height.
Do you work to find out the suitable line-height for your design? It’s Simple. Only multiply (the font size * 1.5 or 1.618 or 1.61). These sizes are suitable for any design.
For example, The font size is 12 pt.
You just apply this rules: (Font size * 1.5) = (12*1.5) = 18
This 18 is the best line-height. You must apply these rules to all your designs and you will find the best result.
Rules Number #2:
The letter Breathe.
These rules are too much important than other rules. In this situation, you must be remembered that you need all the time to sure that you must have a bigger gap between different text blocks than within one block.
Let’s see this image!

Rules Number #3:
Confused on The font size?
The best uses method in the design world is 2X rules. This rule too vital in the design section. Suppose, you are trying to use 30 for your design header. You can pick 15 for your body text. When you use this method you will be surprised.
Always keep in the main 2X rules.
For example, The Body text font size is 30 pt.
You can apply this rules: (Body text size * 2) = (30* 2) = 60pt.
Now the header font size is 60pt.

Rules Number #4:
Confused on Alignment?
It’s too much easy than other rules. All-time be critical and must check your alignment.
As usual, when you put some Body text you can align the left. Because it’s easy to read the text.
Let’s check these images.

Rules Number #5:
Use 1 – 2 fonts in your design.
These rules are important than 1 to 4 rules. Try to use these ticks. You should not use pair of SERIF + SERIF or BOLD + BOLD. You can try this special method.
Try to use this type pair (BOLD + REGULAR) or (REGULAR + BOLD) totally depend on your practice.
I hope if you apply these methods in your design, I think you will see the improvement of typography arts in your daily work.
These rules are made by Many Famous Designers. Who has working to find out the best typography rules for us . If you think these rules are important and helpful you can share it.