I dose individually with a 3-part container that holds 1500ml each, but I only fill each (especially alk) with enough solution to last 3 to 4 days. That way, even if I have a (mechanical or human) problem right after filling, the resulting levels will not cause enough of a spike to severely affect the corals.
This is a personal methodology and works for me because I check levels every day or 2. Sometimes I need to add a little more or back-off a little, depending on the levels created by regular water-changes. I do this with dosing pumps controlled on Apex channels. Occasionally I accidently leave it on ON, rather than AUTO.
It is very easy and accurate for me and I haven't had a huge Alk, Cal or Mag dump in years. I am a huge fan of redundant back-ups in as many aspects of my tank as possible. That is tough to do with a Ca reactor or large dosing containers.