You should use KB size pictures in your website because heavy size pictures can take much loading time of a website.

Hi EventInDelhi777,

You can always compress your images and reduce server response time, enable cache and evaluate plugins.

For best practice
Use the best Server
Use Compressed Images
Do not use the irrelevant code or unnecessary code
Avoid Inline CCS
Do not Use JavaScript if not needed
Make Redirections on place
Keep Web Page Size under 3MB