Use a keyword research tool to find the unique keyword that you want to rank for. Look for keywords with low competition and high search volume.
Long-tail keywords are more specific keywords (that usually consist of 3 and more words) that have lower search volume than the general keywords, but it is much easier to rank for them as the competition is lower as well.
Although the monthly search volume is much lower, the fact is that these keywords usually have higher engagement and conversion rates. For example: if somebody wants to order pizza, he probably types in “pizza delivery in boston”, not “pizza”. Also, there is much bigger amount of possible combinations so you can optimize for more of them.