Paste PCB caps - We use ALPHA Lead-free solder paste (CVP520 42Sn/57 6EW 0.4 Ag - which is kept refrigerated when not in use) together with custom-cut stencils and a Uniprint-M Lift. In between pastes we use Techspray Renew Eco-Stencil UM (1570 LT) and a toothbrush to clean both sides of the stencil. Pasted PCB's need to be populated within half an hour so in the likelihood that populating won't complete immediately any pasted PCBs need to be refrigerated. Note: It's not essential that paste is applied to PCB's in this way, and we do also solder some boards by hand.
Populating - If we don't use a custom-built PnP (Pick and Place) machine we manually populate boards with an EssemTec SMD-Placer.