Step by Step

Here goes a tutorial with photos. you can see i am using an old version of filterstorm.

the new filterstorm is much better and has a more friendly interface.

original image

resize to square format

open the filter menu to see the blur option

put the blur at 100% and choose the mask option. 

on the filterstorm 3 you will see a brush instead of "apply with mask"

put the softness to minimum and the diameter on a medium size to start the blur 

let the details to the end

Put the softness to the max and the diameter to a very little size

it is time to give a big zoom on the image

Go painting the background with big zoom and little brush size.

now it is time save this image

the image without background 

on this case i decided to make the image brighter

with an image like this you can do whatever you want, just go crazy with the apps you have.

 

i open the image on pop! cam of photoforge2,
i like to click on the "random" button and untill i see something i like.

after pop! cam i choose the auto adjustments option to  improve the exposure

i like to adjust the shadows and highlights

And that is it, now it is time to post it on Instagram.

How to...

I think it will be easier to understand the process visualizing the steps.
As soon as I write a detailed explanation I'll post here, but in the meantime feel free to look in the comments posted on Instagram.