Read for the five anchors, not the whole page
Before you transcribe a single sentence, pull out the five things a tree is built from: people, dates, places, relationships, and events. These are the load-bearing facts. Everything else is colour you can come back to.
Reading this way changes what you look at. You stop trying to decode every flourish and start hunting for capital letters (names), numerals and month words (dates), and the prepositions that mark places (at, of, in). The page gets smaller and the work gets honest.
Learn the half-dozen letterforms that actually trip people
You do not need a palaeography degree. You need to recognise the few shapes that recur: the long s that looks like an f, the double s written as a single tall stroke, terminal flourishes that add a loop to the end of a name that is not a letter, and ditto marks down a column that mean the value above repeats.
When a name still will not resolve, compare it against a relative whose spelling you already know from another record. A surname you can read on a census becomes the key to the same hand on a letter. You are not decoding in isolation; you are matching against what you already hold.
Leave it illegible before you let it be wrong
The cardinal rule: an honest blank beats a confident guess. A misread name propagates through a tree and corrupts every record you attach to it. If a stretch is illegible, mark it illegible and move on. You can return with a better scan or a second pair of eyes.
And keep the image. The scan is the source of truth; your reading is a layer on top of it that anyone can check later. Never let a transcription quietly replace the document it came from.