So, for my money sites directly, I submit to GSC. Then go to social media and make posts on the corresponding pages with the new article link. I check back & monitor whether or not the new link indexes.
For backlinks, I do a variety of this, but what I first do is submit to speedlinks & 1 indexer. Sometimes I send backlinks to those backlinks depending on what they are. This works for me 9 times out of 10.
Since the problems indexing last year that everyone was having, indexing has been much easier.