What are some tips before you visit Vietnam?

Here's my personal itinerary. I decided to skip the beaches, which are supposed to be gorgeous, because I had already spent enough time on Thailand's beaches.

Well, this is quite a broad subject... Are you asking for places to see, things to do, or general tips?

First tip is to do your research. Vietnam is a long stretch of land and there's a lot to see. If you have limited time, you probably have to pick a few cities you really like. You can ask for recommendations on Quora but everyone has different preferences, so I would start with Wikitravel for a simple overview and go from there.

Here's my personal itinerary. I decided to skip the beaches, which are supposed to be gorgeous, because I had already spent enough time on Thailand's beaches. Instead, I (or my group) chose the following:

Hanoi Vietnam - For its history and museums, and access to Halong Bay/Sapa

Halong Bay - UNESCO site and natural beauty

Sapa - Hidden in the mountain with traditional villages and rice terraces

Ho Chi Minh City/Saigon - I would say this is what I imagined modern Vietnam travel to look like. Also if you want to experience good night life and visit the Cu Chi Tunnels. Can add a side trip to the river deltas as well.

Other places I would have liked to visit are Hoi An, Hue, Da Nang, that are more in the central part of Vietnam.

Other random tips:
- Vietnamese food is amazing. I did a foodie tour in Saigon (on the back of motorcycles driven by cute Vietnamese girls in traditional dresses!) and it was wonderful.
- You can't get into nice clubs with flip flops :/
- Egg + coffee. Why don't they make those here?
- Rent a scooter and ride around the country if you are the adventurous type.
- When crossing the street, just walk and don't stop. The motorcycles look like they are running you over but they all know how to avoid tourists.
- When in Halong Bay, there are the party boats, and there are the slightly-more-luxurious-boats-where-people-go-to-bed-at-10.
- Cipro works wonders.