A service like BrightEdge comes with the biggest costs associated, but its SaaS solution for SEO covers many areas inside of a single ecosystem, including the ability to explore keyword data. This may be a benefit for agencies that wish to reduce redundancies across vendors, but eventually, it is likely that the need for a second tool will present itself as talent and effort levels increase inside of your SEO department.
Well there are a few things I look for (I will produce a bonus video about this topic and add it to the other bonus video tutorial) but basically I like to see sites like forums/niche sites/Q&A sites in the top 10 along with other things like sites that are not targeting exact keyword in title/meta, sites with low page authority and domain authority, sites that are less than 3 years old etc etc
If you don't know the difference between head terms and long-tail keywords, let me explain. Head terms are keywords phrases that are generally shorter and more generic -- they're typically just one to three words in length, depending on who you talk to. Long-tail keywords, on the other hand, are longer keyword phrases usually containing three or more words.