So, you’ve created a schematic which probably included a new component, saved the schematic’s netlist, ran CVPcb to associate your components with their footprints. At this point, you’ve realized that some components, especially those you created yourself do not have their respective footprints. So you saved your footprint association, closed that window and probably generated the netlist once more. What to do?
We will assume that the component whose footprint is missing is the TPS60400 whose datasheet shows that it has 5 pins. Following this and this posts, create a new TPS60400 component. You don’t have to have a circuit around it. Annotate and Generate netlist. Click on ‘Run Pcbnew to layout printed circuit board’. A new window appears. Click on ‘Open footprint editor’ then follow the instruction in the video below:
Remember to consult your datasheet for the dimensions and sizes of the pins and the distances between the pins. The video was just a general example of how to create a footprint