The downbeat borrows its weight from the beat before it
When the verse kick, bass, chords, and ad-libs all run at the same density to the bar line, the chorus sounds less like a new scene than another layer placed on top. A crash and more sub on beat one cannot create much impact when the ear is already full. The useful decision is not how to make the chorus larger, but when the previous bar will begin giving space back.
Remove the final kick and the low end gains somewhere to land. Shorten the chord release and the first chorus harmony gets a clean outline. Or let one final vocal note cross the boundary so the sentence continues while the instruments clear. Contrast does not require total silence. It comes from deciding what stops and what is allowed to keep speaking.
Choose the handoff before adding a fill
When a section does not turn cleanly, a drum fill is an easy first answer. But a fill marks the border; it does not explain the relationship between the rooms on either side. If snares and toms occupy every gap, they compete with the new information on the chorus downbeat. First give one element the job of carrying the boundary: a short reversed cymbal, a single bass pickup, a vocal inhale, or a delay thrown on one word.
One carrier is often enough. If the vocal breath opens the next section, the drums can leave the final half-beat alone. If the bass already points toward the arrival, a rising effect does not need to repeat the same gesture. Judge a transition element by whether it receives the end of one section and places it precisely on the first beat of the next, not by how spectacular it sounds in solo.
Loop four bars and listen only to the boundary
Playing the whole arrangement from the top makes the story familiar, and familiarity can make an awkward transition seem acceptable. Loop only the last two bars of the outgoing section and the first two bars of the new one. In that small frame, a lyric that closes too late, low end that never breathes, or too many attacks stacked on beat one becomes obvious.
Mute every transition effect first and listen to the rhythm section with the lead vocal. If the boundary still reads, the effects can remain as decoration that sharpens direction. If it does not, change the final kick, bass length, chord voicing, and vocal tail one at a time before adding a riser. A good transition is not clear because it contains more sound. It is clear because the previous bar returns the space the new section needs on time.