Two months backpacking through Europe, traveling solo as a woman. Any tips would be appreciated! This will be my first time traveling solo longer than a week. I'm fairly physically fit and late 20s. Any tips on solo travel and especially safety as a woman traveling alone would be appreciated.

My current itinerary, in order is:

* Madrid
* Rome
* Naples
* Florence
* Milan
* Vienna
* Berlin
* Frankfurt
* London
* Edinburgh
* Dublin

I'll be spending about 5 days in each location, plus travel time. I'll be staying in hostels and using trains where possible, though I will be flying from Madrid to Rome, Frankfurt to London, and Edinburgh to Dublin.

I plan on packing for the trip in a 40L backpack, making use of hostel laundry facilities so that I really only need to pack about a week's worth of clothing. Any suggestions on what extra to pack for staying in hostels? I already know to have locks, flip-flops, and a towel.