Help me improve my dire first attempt at soldering

I'm using this solder http://m.ebay.co.uk/itm?itemId=161281534343

I have been using 350C temp on my hakko fx888d iron. I see the solder melting point is 183C. Is this perhaps one of the problems?

Specifications

63/37 rosin core solder.
Flux 2.0%.
Wire diameter: 0.8mm.
Melting point: 361°F/183°C.