How to take Screenshot on Raspberry Pi

I hate it when i am delightly achieving something on my web application development but no one is seeing it! Therefore today i am determined to print the screen of my Raspberry Pi!
These are the few methods that i took:

Using phone camera – No good. it’s glarry and i’m lazy to upload it.
Using Imagemagick which is pre-installed in Raspberry Pi. I pressed the printscreen key on the keyboard and attempt to paste it on that software. Failed.
Open up a new terminal, type the following:
sleep 5; import -window root myscreen.png // printscreen after 5 seconds
This is what i got.

imagemagick printscreen
Type
import -window root screen.png
This is the black screen that i got.

imagemagick printscreen
At the browser window, i right click and “save page as” webapp and save it in home/pi. Then i transfer it to my laptop using Core FTP LE. Can’t open an unknown file.
Save as webapp.html and transfer it over. Design not displaying properly.
Move it to the folder where all my web app python files are. Open it using mozilla firefox and press the printscreen button on my laptop.