One change from this year, and one for next year:

Dress Code

Sorry football fans…but from this year, spectators are requested to dress smartly in the arena. The Event Promoter requests that no sportswear or team sport shirts are worn. If in the opinion of the Event Promoter an item of clothing is not deemed suitable to wear in the arena the person will be refused admission until such time they have found an alternative item of clothing that is deemed acceptable.
This seems petty to me and if I owned any sportswear I'd probably wear it under my shirt into the arena and then take the shirt off.

However, some promising signs regarding ticketing for the 2019 tournament:

This year, for the first time, tickets on the first day of sale will be available ONLY to fans who are able to book in person at the Crucible box office.

These seats go on sale at 9am on Sunday, May 6 and will be limited to a third of the tickets available for sale. Fans will be able to buy a maximum of four tickets per person per session, and the actual tickets will not be sent out until a month before the 2019 tournament. This approach is being introduced to limit the ability of secondary ticketing providers (or ‘touts’) from purchasing tickets and preventing real fans from accessing them at the advertised price.

The remaining two thirds will be available online, by telephone and in person from 9am on Monday, May 7.
I must say I welcome this approach as a good start, and it's farewell to Viagogo too!

World Snooker has also taken the decision to cease sales through secondary markets, and they are committed to diligently policing these markets and taking appropriate measures, including cancelling the tickets that can be identified.