Budget wisely. Airfare to Europe in the peak season will likely cost you more money. Carefully research your options to make the most budget friendly flight plans, even if it means you fly into one city and fly out of another. If you are flying for free thanks to points, make sure you book early.
Plan for a crowd. If you are going to travel during peak season, prepare for peak season crowds. Keep this in mind if you have limited time to spend and you wish to check out popular attractions. Be especially mindful of tour buses, which can dominate certain museums and attractions during the main part of the day.
Arrive early, or even late. Even on your vacation you'll benefit from getting up early to beat the crowds at popular locations. Even later in the day when tourists have scattered to forage for food or a taste of the nightlife can leave you to explore some of the best of the cities in peace.
Don't be afraid to explore the neighborhoods and see Europe the way the locals do. Sometimes just streets away from more popular attractions you can find little hidden jewels which offer a more authentic side of the country. Find funky boutiques or cafes popular with the locals of the city, or skip crowded restaurants and get your food to go. Enjoy a picnic in a park or even explore the countryside, especially in the northern countries of Europe.
Take advantage of the warmer weather in July to walk to your destinations. Skip the price of the taxis and metros, which skirt you past neighborhoods full of photo opportunities and that authentic European flavor that often gets passed by. Also consider renting a car so that you can explore back roads between cities, and drive to less crowded areas of Europe that aren't as promoted.
Dress light, and pack lighter. Be a savvy packer and use comfortable, breathable fabric in classic staples of clothes you can mix and match depending on the occasion. Invest in good walking shoes that you can wear any time, from casual to semi-dressy.