I used a typical water drum, with the top cut off to make a lid. I made some slight modifications with the existing rain water drain pipe at the side of the house.
Step 1: Cutting the Top Off
With a hacksaw, I made an initial cut just below rim (about 2 to 3 cm below the rim). I go all around but I don't cut through. This is to make it easier when I actually start cutting with the electric jigsaw. Caution: wear proper personal protective equipment when using power tools.
Step 2: After the Cut
Once complete, it should look like this. Clean up any plastic fillings from the work area and wash the inside with clean water.
Step 3: Cutting the Rain Water Pipe
This part was easy because the pvc pipe is thin. I didn't take a picture of the cutting process, but what I did was use a hacksaw to cut horizontally on the pipe. Once done, see if the water drum can be placed just below the cut pipe. Otherwise, like me, I made a minor adjustment to aid the water flow. I used an old old container and cut out into half diagonally. You can look around the house for other similar items.
Now all I need is the rain.
This is my first project. Cheers!