Placement of resistors.

Using the right tool helps alot, but alot of it is practice
id suggest practicing on similiar size smd parts before you go for broke with the ones you bought
I collect all sorts of scrap boards, some of it very dense smd boards
I wipe them entirely clean with a toaster oven and sort out the smd parts, then when I want to practice I take the newly cleaned board and try to resolder the parts, its great practice