This is what Accely do to create an ICON for CONTROL.
Please find the steps for below for icons for ControlERP. Hope this is useful.
1) Check for high quality image for Icon on Google or other relevant website.
2) Then Resize the image using Photoshop.
3) Image Dimensions: 350x312 pixels
4) Add Icon Description.
5) Font: Roboto
6) Font Size: 47
7) Make background transparent.
8) Save the image in png format