I use Ignition and I use their three-tiered model to sell planning services upfront. I send my proposals in January. Tier 1 is just tax prep, Tier 2 adds "quick questions" (no calcs, no opening planning software, no extensive research), and Tier 3 is one (or more) deep dive planning session(s). I quote it all flat-fee based on complexity of the tax situation and what they want to cover (or what would be applicable in planning).

If you don't currently use Ignition, get a referral link so you and the referrer get a kickback. If you don't have someone to get a link from, reach out to me and I'll share mine, I don't think it works to put links in here. My last name is Strube, find me on Google or LinkedIn.