Tube top fashion was quite popular in olden days. If you remember seeing any of Mahaharta,Ramayana episodes you will find women wearing tube tops with long ghagra or sari. Later these tops fashion died down here and became quite popular in west.
General problem with these tops are that you feel it might fall off. Also if it goes little down your upper body portion might show what is not required .
Therefore two points should be kept in mind while wearing them.
1.Women with which are heavy breasted should avoid it. Even if you still can’t resist it then wear a strapless bra or a bra which has invisible straps.
2.If you are planning to wear it on a beach then wear a string halter bikini top in a contrasting color underneath.
3.To keep modest on top and cover cleavage you can wear a tube top normally as a top, but underneath another shirt.
Below here are some tube tops which are ideal in this summer.