There are several techniques to speed up the initial page load time including concatenating files, removing unnecessary code, compressing files with gzip, leveraging caching, and using sprites. Specifically: 1) Concatenating JavaScript and CSS files into single files reduces the number of HTTP requests needed. 2) Gzip compression can reduce file sizes by 60% and decrease download times by 45%. 3) Setting long cache expiration headers and versioning files ensures browsers cache static assets so they are not downloaded on subsequent visits. 4) Sprites combine multiple images into a single image to reduce the number of image requests.