Clothing/Shoes/Weather Gear: Even when you visit in peak season in summer, keep in mind that there can be strong winds and rain. So bring a wind stopper or rain jacket and umbrella. You may be amazed to see people swimming in the sea whereas others are packed up quite wind proof.
Toiletries and Medical Supplies: Sunscreen, beware of the wind!
Photo Equipment: If you have a digital camera you may want to make sure you have enough batteries or your battery charger with you. I had to sun around several shops to find Lithium batteries and the vendor said that I was buying the wrong one (which wasn't true), it was the only one in stock. So be prepared.
Miscellaneous: Note that some public toilets only give very little toilet paper. You may find it a good idea to carry a bit on you.
What to take with you
Clothing/Shoes/Weather Gear: It's not always hot and sunny in the summer time. So, it would be wise to take a sweater or a jacket with you, as it can be cold in the evenings or it might rain during all day.
Photo Equipment: Don't forget to take your photo camera. The sunsets are just wonderful here, as well as some other touristic spots.
Toiletries and Medical Supplies: If you are coming to Palanga for a private accomodation, don't forget the towels.
You will not find it on toilet, in 90% of cases.