Here are the steps to write in mando tab:
1. Create a grid of six horizontal lines, representing the strings of the mandolin.
2. Number the lines from bottom to top, with 1 being the lowest (6th) string and 6 being the highest (1st) string.
3. Write numbers on the lines to indicate which fret should be played. A "0" indicates that the string should be played open (not fretted).
4. If a note is played more than once in a row, the numbers can be connected with a slur (a curved line).
5. To indicate a chord, write the fret numbers for all the strings that are being played simultaneously.
6. If a note is plucked with a pick, a small "x" can be written next to the number.
7. If a note is fingerpicked, a small "i" can be written next to the number.
8. If a note is hammered-on or pulled-off, a small "h" or "p" can be written next to the number.
Example:
```
|6|--0--5-----------------|
|5|--0--5-0---------------|
|4|-----4------4--2--4-----|
|3|--2------------2--2-----|
|2|-------------3----------|
|1|------------------------|
```
This tablature represents the chords G major, D major, and A major, played on the mandolin.