I agree, comments are Open & more welcome!
But, different comments, different ideas on which few may be good & few maybe bad idea.
None think - This makes OP to get in confused
Op Mind after reading posts..
whether I go for web 2.0 like man 1 Suggested.
or whether i go with guest posting like man 2 suggested
or whether try authority links like man 3 suggested
No No i'm totally confused which one is best to go with

lol
The keywords that i am testing has very low traffic.
Do more web 2.0?
If Keywords has very low traffic, then test with few web 2.0 links as you wish - if testing fails, Go for Plan B
like wise, test with other type of links i.e PBN, guest posts authority - if testing failes, Go for Plan C or D
If testing Works, Results Driven! then Keep going with the Plan for all the other keywords & Improve your Rankings.