Before you go to Port Phasmatys, bank everything you need except bones, buckets and pots. And if you want prayer xp, I recommend bringing the best bones you can get. D bones if you can, big bones if not.
Get an extra bucket of slime, and use the bucket of slime on the bedsheet, rather than taking the sheet to the slime pool. This way you do not have to leave the town to do that.
"Instead, use your unused bucket of slime you've got at the beginning of the quest with the bed linen (you may have stored it in your bank), then return back to the town."
You may want to mention. If you did not grab an extra bucket of slime, you will have to leave the town, take the linen to the slime pool and use it on the pool, then return to town.