A few tips I've learned over the years for playing/cashing:
I always play at places that I KNOW have cashflow (and only play at 2/3 spots total so they remember me). News agencies, tobacco shops, and convencience stores that promote money transfers such as Western Union and have high lottery sales are safe bets. Avoid 7/11, small gas stations, and lottery ticket machines like the plague. Always be friendly with the employees and make it a point to get to know the owner. When I hit 528 for 5,000 in May, I called ahead of time to the spot I played and asked how many I could cash that day... they said come in at 6 pm and get all of it!
And most importantly, when you cash a ticket, tip a little bit! The next time you go to cash a ticket, I promise they will have the money ready for you.
I do agree that more places should be responsible for paying out tickets, but the truth is many do not care! I refuse to give my business to places I know will not return the favor when I hit!
Hope this helps a little, good luck everyone!