The best way is to ensure that you are using all or the main academic media/social media outlets that are available to you. You are obviously already on ResearchGate and can upload to there. Next best thing is to set up your ORCID account. It mostly updates itself as doi numbers become available and transfers to many other sites automatically. Similarly, you can set up your ISI ResearcherID - which works in conjunction with ORCID and Clarivate (ISI). If you have published with Elsevier then set up Mendeley. Again - it self-populates. Google Scholar also self-populates as does Scopus. You have to set up your own profile on sites like this for citation metrics etc. The main types of sites where you have to upload your own publications (unless prompted by those sites) are ResearchGate, Academia.Edu and GrowKudos. They are well worth the effort in my mind. Publons is another self-populating site - and works in conjunction with peer manuscript reviews that you may have performed or will perform. I use all of these formats and they work well (and in different ways) to 'share' my publications with the wider, international academic community.
You are on the right place to make your publications more visible. Just click on the blue button on the upper right on any Researchgate page (when logged in), marked ”ADD NEW” and follow instructions.
However, you have to check what the journal you have published in originally allows. Some allow publishing with their layout, other allow publishing of the manuscript, not the layout journal version, some demand you wait a year or two, some want you to pay for open access to your own publication (very unreasonable, my personal meaning) etc. You can, I think, always publish the abstract.
Check these conditions for sharing on the website of the journal, or just check here http://www.sherpa.ac.uk/romeo/journalbrowse.php if the journal in question is a Romeo green, yellow,, blue, white, etc ...journal, which is a code for conditions. You want Romeo green or yellow or possibly blue for sharing your publication on Researchgate. Romeo white journals are tricky, avoid these journals in the first place is my advice, do not submit. It is important to make ones publications accessible. Hope this helps!