How editors actually find reviewers
Most invitations come from the reference list. When a handling editor receives a submission, they look at who is cited, who works on adjacent problems, and who has published in the journal recently. If your work is in that neighbourhood, your name surfaces.
Journals also keep reviewer databases populated from their own authors. Publishing in a journal usually puts you in its pool, which is why the first invitation often comes from somewhere you have published.
Some editors search databases directly by keyword, and some ask authors for suggestions — which occasionally routes an invitation to you through someone you have never met.
The consequence is that visibility and review invitations are the same phenomenon seen from two sides. There is no separate application process for most journals.
There is no application process at most journals. Editors search the literature, so being findable in it is the mechanism.
Making yourself findable
Keep your author profiles accurate and current — Scopus, Web of Science and ORCID. An editor checking whether you are the right person looks at what you have published, and a fragmented or stale profile makes you look narrower than you are.
Register on the reviewer platforms your target journals use. Many publishers run their own systems, and several journals let you volunteer directly through a form in the submission portal.
Tell editors you have worked with. If you have published in a journal, a short note to the handling editor saying you are available to review in a specific area is entirely normal — journals are chronically short of qualified reviewers, and a specific offer from a known author is useful rather than presumptuous.
Be concrete about the area. "I am available to review" is less useful than naming the two or three topics you can assess properly.
Handling the first invitation
Check the journal before accepting. A venue with no genuine review process cannot evidence that you reviewed to a professional standard, and appearing on its masthead is a liability rather than a credential.
Then check yourself: are you genuinely competent to assess this manuscript, and do you have a conflict? Declining because a paper is outside your expertise is respected. Reviewing badly outside it is not.
Respond quickly either way. Editors remember reviewers who reply promptly, including those who decline promptly — a fast no lets them approach someone else the same day, and it is one of the more reliable ways to be asked again.
If you decline, suggesting a better-suited colleague is genuinely helpful and is remembered.