Create or purchase an icon set
Separate icons into individual layers. Press on the 4 line icon in the top right corner of the layers panel. Then press Release to Layers (sequence) option.
Select all of the icon layers and drag them outside of container layer.
Put container layer into trash. You no longer need it.
Rename all of the icon layers. This is an important step as the layer names are used for accessibility during conversion.
Align all of the icons vertically and horizontally on the artboard.
Resize the artboard to fit the icons. Leave a little bit of space.
Select save or save a copy.
Select SVG or SVG Compressed format.
Don't press ok, press the SVG code... button.
Copy the SVG code from the text document created.
Set the accessibility as required. Read GitHub page for more information on the two types.
Paste the SVG code into the first black box, titled 'Paste raw SVG code here'. Press 'Convert SVG code' button.
Copy the converted SVG code from black box title 'SVG as symbols'.
Paste the converted SVG code into head section of website code.
The black section titled 'HTML svg use' contains all of the HTML for each of the icons. Copy required HTML.
Paste the HTML of each icon into your website where required. Somewhere inside the body section.
Copy CSS from black box title 'CSS'.
Paste CSS in inlne style tag or external style sheet. You can tweek CSS as required. Look into some of the resources on the GitHub page for more on styling SVGs
Open your page in the browser and you should be able to see the icons.