An ideal illumination of the mine entrance with the help of lava. The lava flows behind a glass wall. The lava is much brighter than torches would be and you only need one lava bucket as the lava flows down.

Instructions:

Since lava generates a lot of heat you have to be careful that there are no wooden objects nearby. If your house, where the mine entrance starts, is built of wood, you can start with the lava lighting a bit further down.
First excavate the "staircase" in which the lava should flow at the end. Since glass blocks will be placed in front of it, the hole must be 2 blocks deep. Since the lava does not fill the whole block in terms of height, you can still see some of the blocks at the back and top. So you should also replace them with a uniform material if you want to have that. Then cover the front row completely with glass so that the lava can flow safely. Leave the top glass block out for now so you can place the lava. Then place the lava and immediately after that the glass block and wait until the lava has flowed to the bottom.