Images are usually the largest part of a page. Fixing them often halves load time with no other change.
IMAGES
Resize before uploading. A 4000-pixel photo displayed in a 600-pixel space wastes bandwidth on every single visit.
Use the right format: JPEG for photographs, PNG for logos and transparency, WebP for both where supported, SVG for icons.
Compress with a tool such as ShortPixel or Imagify, or the optimiser built into LiteSpeed Cache. Enable lazy loading so offscreen images load only when scrolled to.
CSS AND JAVASCRIPT
Minify both, which strips whitespace and comments. Combine files where your caching plugin supports it, testing carefully as this is the most common cause of breakage. Remove scripts for features you no longer use. Old sliders and analytics tools are often still loading years later.
FONTS
Limit yourself to two families and only the weights you actually use. Each additional weight is a separate download.
THIRD-PARTY SCRIPTS
Chat widgets, tracking pixels, ad tags and embedded videos are frequently the slowest things on a page, and you control none of their code. Audit them and remove what does not earn its place.