Roleandp gave some tips on getting to Steem Fest:

make sure you have:
-proof of return flight
-proof of medical insurance
-proof of steemfest ticket
-proof of hotel
-invitation letter

A few tips for those who are yet to apply.

• your medical insurance should covers from your flight departure date to the date your return flight date.

• you may consider using Airbnb to reduce cost as some are cheaper in Europe than hotels.

• Attach six months account statement from your bank. If you use more than one bank and all have been active in the last six months, attach all.

• Visa application window is closing. Consider getting all your docs ready so you apply once you have funds.

And if you have any valid visa to any Schengen state till November 13th. Then you don't need to apply as Poland is covered by the same visa.