bandwidth issue mostly happens to new user and to the users who have less steem. So, if you are stuck at 15 initial steem delegated to you by steemit then this problem will happen to you. First week is always with out problem. Based on this first week's usage steem blockchain assigns a quota of bandwidth for the next week. When the users are more at a given period of time, then steemit puts restrictions on user with low steem power. Some times in negative.

One way to overcome this is to spend 1 steem per week and get delegation of 150 steem power from the minnowbooster. This not only helps in gaining more bandwidth but also helps in earning more curation reward.

The second way of getting around it is to use it when most of the users are not active on steem platform. Any one with 15 steem power will get atleast 19 MB bandwidth at that time.

Also, if some one is uploading photos, then it is better to reduce the resolution of the photo using free softwares like photoscape and all. This allows one to retain bandwidth to use later in the day.

Avoid resteeming completely specially when you have steem power between 15 to 30. Resteeming consumes a lot bandwidth. Concentrate on posting your own content more when you are new.

Editing a comment also consumes bandwidth. So, it is always better to check everything twice before hitting that post button. This has helped me a lot. I hope this helps people reading this post and are having this kind of problem.