Section left/right padding 20px on all screen sizes
Column padding 20px all the way around on all screen sizes
Section top/bottom padding can be whatever you like but keep it consistent.
1.) Choose from sequence
2) Top and bottom same as each other
3.) Different Values for responsive
4.) Set the same top/bottom padding on all main content sections down the page ideally.
Separate your sections. Eg. Different Section coloured backgrounds or images etc.
Set column widths in multiples of either:
1.) Thirds (33.33%)
2) Quarters (25%)
Inner sections have zero left/right padding its already covered by the parent section.
A column containing nested sections must have zero padding.
One inner section? All inner sections!