Download the attached file, it can be used in any map. I recommend the Bedroom or the Kitchen, I find the lighting to be just right.
Turn Shadows off in options, it just adds more that you need to edit out later.
Hit F5 to turn off player names, you don't want this in your screenshot.
Stand in the middle of the box.
Use the admin command /spy [your name].
View your player from any angle you want.
Open the console and enter $megashotScaleFactor = 2;.
Close the console.
Take a normal screenshot with Ctrl + P (default).
Close Blockland and open a good image editor program, I personally recommend GIMP.
Use the Select by Color tool, and select the green background.
Delete.
Use the selection tool to create a box around your player.
Crop the image, scale it if you want.
Now you should have a nice, crisp, transparent image of your player.
