Create Custom Symbols for use in ArcGIS Pro

1.    Create your custom symbols and have them saved a .png in a known folder
2.    In ArcGIS Pro, Insert tab, Styles group, choose ‘New’ and ‘Style’
3.    Name and save the new style

You can also add a style you have already created or want to add to.
 

4.     Right click layer, choose ‘Symbology’
5.    Click on ‘Properties’ and ‘Layers”
6.    Change drop down to “Picture marker”
7.    Click ‘File’ to find the previously created .png 

8.    Click on the three lines in the upper right
9.    Choose ‘save symbol to style’
10.    Add name of symbol,category,tags, and choose which style to save it in (probably choose             the style you previously created)
11.    The symbols are now available in the gallery