Re-flow soldering is a subject that many excellent analogue, RF, and digital, electronic engineers, have essentially no knowledge. Historically, there had been two very good reasons for this. Either we just grabbed a bunch of through-hole parts and hand soldered them together to test our ideas, or, if we worked for a larger operation with available budget, we might choose to wait 10 days or so let someone else build it. We never became familiar with the art of solder re-flow.
But if you are going to do your own DPCB, it is a subject we have to become very familiar with.
Re-flow is the term used to describe the process of melting the solder paste to a temperature where the solder in the paste becomes liquid, then will wet to the DPCB conductor and to the component. The assembly is then allowed to cool and leave us with (hopefully) nice looking, clean, reliable solder connections. I highly recommend the wikipedia artical on re-flow soldering.
The last few pages of most electronic component datasheets almost always provide two types of soldering information – infra-red reflow and solder wave.
Your DPCB machine may have come with a built-in solder re-flow ‘profile.’ Give it a chance, see how it does. But also compare it to the profile(s) provided in your datasheets. This will especially important if you are going to mix many types of surface mount packages. It may even affect your choice of component packages.
I prefer gull-wing over J-lead packages because I more easily manually re-do a gull-wing joint compared to a J-lead joint.