How to do Keyword Difficulty Research in 2019?

I consider myself a noob in SEO, Till now I have been relying on manual Keyword Difficulty Research.
What I have been doing is looking for 1st Page of Google and Analyzing PA and DA through Moz Chrome Extension and if all the Pages have lower PA than 40 and fewer backlinks( I research this from SEOQuake Extension) then I used to think that as a Fairy Easy competition and used to approach those keywords.

I use some free Extension/Tools to ease my Process:
Keyword Everywhere - For Determining the Traffic of Keyword ( Along with Google Keyword Planner Range to double check and be sure the data of keyword Everywhere is right)

SEOQuake - For Knowing Backlinks, Age of domain on the SERP page to get a better analysis of ranking results.

MozBar - For PA and DA

To get long tail keywords I use Keyword Shitter along with Soovle and Ubersuggest to get more and more keywords and then I import those keywords on Keyword Everywhere and get myself some fairly easy long tail keywords.

For Backlink Research I use SemRush and BacklinkShitter.

This is what I do actually, but I want to know am I doing it right are there more methods or an easy or better process for Keyword Difficulty Research, Backlink Research or Long Tail Keywords. Seeing LSI keywords in action I am a bit confuse Enlighten me.

you forgot Google keyword tool. It's better in generating related keyword and longtail keyword

Check out this guide here: https://www.blackhatworld.com/seo/g...ompetition-without-spending-a-dollar.1074066/

This is a good case study to measure keyword difficulty. Its not mine nor i am affiliated to this site.
authorityhacker.com/keyword-difficulty-showdown

Well, you were doing it right somewhere but you need to enhance your knowledge by finding out more tools for it.

Kwfinder is also a good tool for check keyword difficulty.

Google AdWords keyword planner helps you to find keyword difficulty always. Its better than other keyword tools.