To display a marker with your own image or icon, you need to define a custom icon in Leaflet. This involves creating a new L.icon object and specifying properties such as the image URL, the icon's size, and how it should be positioned on the map.

First, you use the iconUrl property to set the path to your custom image. The iconSize property determines how large the icon appears on your map, given in pixels as [width, height]. Adjusting this ensures your icon looks crisp and fits your design.

The iconAnchor property is crucial for correct placement. It sets the pixel coordinates within the icon image that will be placed exactly at the marker's location on the map. For example, if your icon is shaped like a pin, you usually want the tip of the pin to sit on the precise geographic point. By tweaking iconAnchor, you control which part of the image aligns with the marker's coordinates.

Another useful property is popupAnchor, which defines where popups will appear relative to the icon. This ensures that popups open in a visually pleasing spot, often just above or beside the icon.

After defining your custom icon, you pass it as the icon option when creating a new marker. This tells Leaflet to use your image instead of the default marker icon. You can then add the marker to your map and bind a popup or other interactive features as usual.