Get the technical basics right
Shopify is a hosted platform, so you do not control everything. You do control enough to matter.
Page speed. Shopify is fast out of the box, then apps and oversized images slow it down. Audit your installed apps and remove anything you are not using, since each one can inject scripts that load on every page. Compress images before upload and lean on Shopify's responsive image handling rather than uploading enormous files.
Mobile. The majority of UK retail traffic is mobile, and Google indexes the mobile version of your site first. Check that menus, filters and the basket work cleanly on a phone, not just that the page renders.
Indexation. Use Google Search Console to see which pages Google has actually indexed. Shopify generates tag pages, filtered collection URLs and search result pages that you rarely want in the index. Thin or duplicate pages crawling your budget is a common drag on otherwise healthy stores.
Structured data. Product schema with price, availability and reviews can earn rich results in the UK search listings, which lifts click-through even when your ranking position has not changed. Good themes include this, but check it validates.
If the technical foundation needs serious work, that often overlaps with a wider build decision, which is where our web design team and SEO specialists tend to work together.