How can I create my own schematic symbol?

Schematic symbols may be created directly without the use of the wizards. This is straight forward and convenient when only a few connections are required, but the 'Wizards' are more recommended for larger pin counts or when a standard component is required.

Launch the Library Manager, select the Schematic tab and select the target folder and then click the 'New Item' button.

The editor screen opens, add your 'terminals', these are the 'pads' on the tool bar for the symbol, (leave your 'style' set as terminal) and place the pads as required at the correct spacing for the schematic symbol. This is actually all that is required by DesignSpark PCB for the connectivity.

You may now add your symbol 'artwork' to create your component using the 'shape ' tools from the tool bar.
Use line styles to be consistent with your other library components. 

Finally tidy up your design as shown above to position the pin name and number in the correct locations. Select the item, choose 'properties' and choose the appropriate alignment.

The symbol is now complete, save in the required schematic library.

See also: What settings should I use for creating schematic symbols?