I've optimized 1,200+ websites over the past few years. The #1 mistake I see with Shopify and WordPress sites? Owners install 15+ apps/plugins and never check what they're doing to their load times.

Here's a quick checklist that fixes 80% of speed issues:

Images — Most sites serve full-resolution images to mobile users. Use WebP format and lazy loading. This alone can cut 2-3 seconds off your load time.

Unused JavaScript — Every Shopify app injects scripts. Go to your PageSpeed Insights report → look at "Reduce unused JavaScript." If it's red, you're bleeding performance.

Server Response Time (TTFB) — If your Time to First Byte is over 600ms, your hosting or theme is the problem. On Shopify, bloated themes are usually the culprit.

Fonts — Custom fonts without font-display: swap cause invisible text flashes. Use system fonts or preload your web fonts.

Third-party scripts — Analytics, chat widgets, review apps — they all add up. Audit them. If you're not actively using it, remove it.

Run your site through PageSpeed Insights (pagespeed.web.dev) right now. If your mobile score is under 50, you're leaving money on the table.

I do this professionally — full audits and hands-on optimization for $99. If you want it done right, check out the product page.