In taking apart and re capping vintage computers, I discovered that factories would often use a small dab of glue for things like smd can caps. Not sure if they did that for other components as well…
It's a pain, full stop. Many folks in the vintage computer repair world have microscopes or magnifying goggles to aid in positioning and even then a steady and patient hand is required (something I really struggle with).
Whatever you do, don't use those (forgive me if there's a proper word) reverse sprung tweezers to hold parts! Learned that the hard way. I find it helpful to gently scoot parts instead of picking them up like a crane, if that makes any sense.
I've had luck with tantalum smd caps this way: put down flux (the proper answer yo 'how much?' is always "yes") then tin the pads, just like jjjimi84 did, and use what solder is there to just get one side soldered on (properly aligning the part, of course), I've found it helpful to gently press down on the part to make sure it's not "floating". Once that side is secure, solder the other side. IME if you tin the pads just right you won't need to add any additional solder, leaving you an extra hand for tweezing.