Myanmar is a country deeply respectful of their religious and cultural traditions. Visitors will be more than welcome if they can note a few things.
Remove shoes and yes, socks too when entering religious buildings or compounds. This means both pagoda compounds and monasteries. Although some Buddhist monasteries allow footwear in their compounds but not inside buildings. So make sure first. Almost all private homes too expect visitors to remove their footwear on entry but not socks.
Gifts are handed over with either both or with the right hand. Use both hands if one is giving a gift to an elder or a senior person. It is to show respect. But visitors can be casual when paying your bill at the cashier after having a meal of course.
Myanmar women would never ride on the roof of public transports, either buses of boats in the old days but nowadays both local and international tourists on Mandalay-Mingun cruises are doing it. Boats plying this route had even re-designed their crafts to let their customers do this and enjoy the scenery. Women also refrain from touching a monk, including his robes. All pagodas and Buddha statues prohibit women climbing up to the upper levels and there are segregated enclosures for women to sit and pray especially at Maha Myat Muni pagoda in Mandalay. However, everybody is allowed to climb up some pagodas in Bagan to view the beautiful Bagan sunset.
There are ready made Myanmar dresses for both male and females in the market. But when men wear their longyis (the lower garment wraps around the lower part of the body) the hem should be lower than one's knees. It is only when one is doing hard manual work the longyi's hem is above the knees. As for women folks, please be reminded that Myanmar ladies' dresses are to be worn with dignity. Going braless is a big no no as well as skimpy western dresses like hot pants and singlets. But some young girls would be seen imitating the Korean starlets in hyper modern dresses especially in big cities like Yangon and Mandalay.