Upgrading the rare weapons before NG+?

[Radford999]

Hi guys. I’ve been following the guide/walkthrough. First of all it is excellent!. I’m just at the end of my first playthrough. I’ve read the next couple of paragraphs about upgrading the remainder of the rare weapons before i start. So i just want to make sure i am doing it right before i begin my second playthrough. 
 

So obviously i need to upgrade all 15 of the special weapons to get the rest of the rare weapons trophy. So am i right in thinking i need to upgrade whatever i can in this playthrough. I.e using all of the boss souls i have got so far to create those weapons. Not only that but the weapons i have not upgraded to the special weapon, i need to upgrade every one up to rank 10. This is so i don’t have to find the embers again right? So in NG+ i can just get the boss souls and upgrade it straight away? I.e no need to find the embers again to upgrade it to rank 10 because it’s already at rank 10. 
 

Thanks!

[WereyCar]

I would farm all the materials you need for each weapon upgrade, and  upload/download save when you complete each one to reduce farming time. As for boss souls, they're kept through NG+ so you won't lose any of those when you move on. Upgrade whatever else you want to use, though personally I never picked anything but the Great Club +15.