The Blast Network Walkthrough that I have designed myself. This Walkthrough is not cheating,but it'll make much people rage at you a lot.
BLAST NETWORK WALKTHROUGH:
1. Free yourself.
2. Avoid other players,stay in the corner most far away from people.
3. Collect pickups,keep spamming bombs in that corner untill 13.
4. Find your cover / run around,dodge attacks.
5. Other people will keep defeating each other,you'll do the listed things in the step 4,and get the most points and lowest number of kills.

Thanks for reading.
Hope this works (it does).
Good luck!