Move blue lines back
Make offside the puck getting pass the red line once it has entered pass the blue line
Put the ringette line in and make shot blocking pass it illegal
Call more penalties
Call penalties consistently
Smaller goalie equipment
Less players on the ice (4v4, 3v3)
Less players on roster(8f, 4d, 2g)
Bigger nets
Bigger ice (width, length, or both)
These are all factors that could increase scoring IMO, but I don't think any ONE thing(besides players on ice, such as 3v3), would cause a significant jump in scoring. Maybe more pp's too, but I just want more penalties called until players learn what a penalty is so there is less obstruction overall(they will stop using so much obstruction when they give up a couple 8 or 10 pp games)
So I would say the same would win +-3 points