What Trick am I Missing to Solve No. 165?

[Gemini]

Before anyone says anything: I have cleared 275 of the game's 280 (as of this moment) main puzzles without assistance or help of any kind; all that remains are the final 5 Fantasy puzzles. I would consider myself considerably above average in terms of Picross/Nonogram skills...

...but Puzzle No. 165 is DESTROYING me... >_<

I have spent nearly 2 1/2 hours on it so far and have barely made much progress. I have a bunch of stuff filled in around the middle and a few corners marked with Xs, but am at a point where I cannot find anything else to work with. The only thing I can think of is that I must be lacking a specific technique from my skill set which is required to solve this puzzle, but I spent an hour looking through online resources and found no tricks I didn't already know. :(

For everyone who's solved No. 165 without assistance, what were the strategies you used to see you through its toughest parts and where can I find more information about those strategies?

[Shadeon]

Yeah, those 40x30 puzzles definitely left me stumped for a good while (especially Meteor Strike, that must've taken me like 6 hours and 3 attempts on No Assist).

Whilst I may not be able to give the best advice (despite me having already cleared all Early Access puzzles on No Assist) as I was definitely just as stumped as you are, my general advice would be to abuse using marks/count as much as possible. Especially the latter on puzzles that size!

Remember that at any one time, at least one row/column can have an X or fill added to it, so if desperate you may have to just look carefully at every row or column even if to find just one square you can sort out. Even adding a single X can make all the difference as that could end up being a vital 'divider' of several numbers; use marks to check where those numbers are able to fit, either on one side or the other on that row/column for instance.

Sorry I can't be of much help though. Don't give up regardless, you'll soon get there!