I preached it for the last 3 years, everyone said I was full of it. Here's proof.

Don't build PBNs, buy links from high quality PBN vendors -- SERPShip.com has a dank network that's going to be around for the long haul.

Building and managing PBNs is a pain in the ass, and the time / money can be better spent buying links from reputable vendors. If / when Matt Diggity opens his network up again, jump on board.

Find your top 10 biggest competitors, and "skyscraper" their posts. Don't waste money being original, when they've laid the groundwork for you.

Start from the top of your sales funnel (highest converting offer or pages first) then work down into the social side.

As far as backlink trackers go, Majestic is OK. AHrefs is OK. SEMRush is OK. They're useless if you're not going to dig in and spend your hours replicating the links, though. You can do hella damage with the free trials, download as many links as you can, then spend the next 6 months replicating the easy wins. Then buy PBN links to spot rank the high converting pages on your site.

if you want a tool that gives you a few ideas thats fine but honestly most keyword research tools are no better than Google's keyword planner and nowadays you need to see ad placement for the term as well now that google dumps a lot in the organic column up top and tools haven't yet incorporated that yet. Content marketing does work with a bit of networking . For example lots of bloggers are open to linking to sites of people who contribute to their own site with comments etc. especially if tis good content. Email outreach is slow but also works

Well this is why you might have just read that I contribute nothing but BS because if you don't recommend PBns for every situation then there are a few on here friends with someone who still widely pushes them and training for them who get all upset.

Building a really good one can cost many thousands of dollars for the best domains. IF you already have one of course still good to use them but if you are in a niche or going after keywords with a lot of top spots taken by adwords does it really make sense to spend thousands of dollars to show up still below the fold at position five. I don't think so.

Plus now with pagerank effectively gone (totally invisible to the public) buying is a crap shoot at auctions etc and you never know when you might lose a big investment domain. If your content marketing strategy is working stick with it.

IF you are looking to go in light with less than top power domains then drop catching is a good way to go. It used to be better but now a lot of drop catching outfits are now catching for auctions. A few are not and you can pick up a moderate to low strength domain for $35 or so .

I can't attest to its value now but software used to catch a few for registration fees like this one

Expired Domain Drop Catching Software: Drop Catch Deleted Domains

for that to work with registrars like Dynadot they have to not be wanted as much but you might pick up a couple on the cheap especially now that there is uncertainty as to value.

Foreign domains that everyone could register for used to be another option if you had a registrar agent that bought for them. Australia,canada and a few others used to be decent

I just can't see going all in like a few years back with domains for many hundreds and thousands unless you have some serious cash and can take potential loss. unknown to this crowd here the most widely used SEO tactic is link outreach and emailing webmasters for links. You of course have to have great content to even try that and it is hit and miss.

Also don't rule out directories - not the big multi subject ones but the specialized ones like for a city or a kind of business (farmers, accountants). They have rules as to who can join., sometimes there are fees but you can do some serious damage with them over time. The accepted blanket statements that all directories are the same and bad is just false. In professional niches you see sites all the time ranking with specialized directory link ( moderated not free for alls)

just a few thoughts off the top of my head.