It's quite easy and since it's my first time, I will say I did quite Okay only. I mean it would have been nicer and better but practice makes perfect! I will show vaguely how I did it.
All nail colours are from Elianto. Not only it's cheap but it's quite good quality so it does not burn a hole in your pocket!
Firstly, I painted a base colour using Magenta. Wait for it to be thoroughly dry. This is very important! Be patient, don't rush into sponge-ing just yet.
Then use any kind of sponge will do. This is a face sponge which I cut it into this shape for easy usage.
As I said, I purposely cut it into this shape, because I wanted a flat straight end which would be easier to sponge on your nails.
Then start sponge-ing!! Dab slowly on your nails...
And ta-dah! 3/4 of the nails is sponged with the blue colour. Yes, it's messy and it's not very nice. But wait, it's not done yet!
After that, I used a lighter blue in Cyber Sky colour and painted at the edge of the sponge.
I sponged it again on my nails so that the blue would have a gradient effect. The tip of the nail is thicker with lighter blue and the middle is darker blue and lastly the magenta colour base.
Clean the sides of the nails and top it off with a top coat.
The colours pop with flash...
And my toe nails is actually purple but it doesn't show in picture. It's colour S10 from Elianto as well.
My nails <3
Try the sponge method! It's fun and nice to experiment with! =)