These are a few strageties I though of over the past weeks on Newgrounds. See if they help:

1: If the creator's comments say "don't blam this" or something related to it, there is a HIGH chance of it being a bad flash, so check it fully.

2: If the Title and/or authors comments say random things like"asdfjkl;", its a VERY HIGH chance of it being spam, or stolen.

3: If the title or the comment says a curse like "F@#$ YOU!" its propably garbage or hateful, but not all of them.

4: If the graphics are not good, but lasts for over 2 min. theres a good chance of the creator puting time and effort into a flash, so vote fairly.

Hopefully this is helpful to you. Leave a comment and I will respond. Any comments with hurtful or hateful words or phrases that insult me will be deleted and the person will be banned without hesitation.