Changing to a different file format can dramatically decrease the file size of an image.
GIF is ideal for images with few colors like logos.
JPEG is great for images with lots of colors and details like photographs.
PNG is the choice when you need high quality transparent images.
You can use the external style sheets, minimum images, decrease the file size of the images that we use, without compromising on the quality and use the CSS sprites to regulate the HTTP requests.
10 Ways to Speed Up Your Website:
1. Minimize HTTP Requests
2. Reduce server response time
3. Enable compression
4. Enable browser caching
5. Minify Resources
6. Optimize images
7. Optimize CSS Delivery
8. Prioritize above-the-fold content
9. Reduce the number of plugins you use on your site
10. Reduce redirects
I Completely Agree with @MinishNisha , Mostly all those implement we need to do. For increasing speed of website. Reloading speed most helpful for increasing website.
This is the most important thing that you can do to decrease web page load time. Let me explain it a bit. Mostly bloggers use online available themes. These themes are designed to fulfill the purpose of dynamic website that can use for any website. Hence for displaying site title, meta type, author information, footer it makes unnecessary calls of PHP functions to fetch the information filled in the WordPress Dashboard theme section.
Though it is an easy for novice bloggers to fill information about their website using a menu driven interface. But we can decrease web page load time to make it static. You can make Headers and Footers as much static as you can. As for every page of your website same Headers and footers will be displayed.