Research on the materials
The size of the clothing is important and so is the material of the clothing. There is nothing worse than when you receive a dress that you have been wanting for months just to find that the fabric is of a poor quality. Since you cannot touch the clothing fabric you cannot figure out what the material of the dress is just when you look at the picture on the site. It is good if you can familiarise yourself with what the fabric content is.
Check your closet and find which material you feel comfortable in and which materials make you feel stuffy and itchy. Make a note of the composition of the material of each of these clothing. This can be used as a reference when you shop for clothes online. If you do not like to wear polyester then you know that you have to filter your choices on the online site accordingly.
Check for videos
Photos may not be able to give a clear idea of the dress. So if possible you should check out the video of the dress. There are some online sites that post the video of the model who is wearing the dress. This gives you a better idea of what you can expect out of the clothing.
It could very much happen that the colour that you see on the screen is not what you may get. It is also possible that the colour of the clothing that you see online may change form one batch to another. There could be a slight variation in the colour. You need to be a bit flexible on this because it is a part of shopping for clothes online,. However, there is always an option to return the product if the colour is absolutely different from what you see online.
Return policies could also actually make you disappointed. So make sure that you carefully go through the return policy before you order for any clothing online. There should be an option for free return. Also make sure to note down the number of days in which you should be sending your order back. You should check whether you can make exchanges on the site. There could be some sites that charge a fee on returning the product. You may want to stay clear of such sites.