JPF Home Page Forums Lyric and MP3 Feedback Lyric Feedback Forum 3 Drum Sum

I think you're on the right track for methodology.
Even in an instrumental composition, attention to 'Musical Movements', component parts, could serve the finished product, establishing an appreciable Structure.
I identify the Introductory Movement, and the 'Enough' concept, the Songwriter's Judgment Call regarding 'Enough', 'Not Enough', and 'Too Much'. The Introductory Movement need only be 'Long Enough' to serve that function, to Hook listener interest, and keep them Hooked until the next Movement commences.
The next Movement may be a Verse I, or a Chorus. It is conceivable a Bridge might be the next Movement after the Introductory Movement, or even a Coda, the final Musical Movement in a Composition. All the component parts have a wide range of possible arrangements. If it works, it works. If a Composer found a way to 'open' their Composition with the same Musical Movement with which they end it, and it works, it works.
If opening with Introductory Movement, Verse I Movement, it is likely you can go to the Chorus Movement next.
The Composer's/Songwriter's Judgment Call is in constant application.
Is Verse I adequate, 'Enough', Musically, Melodically, Lyrically, to merit moving on to the Chorus, summing up the essential Idea of the Song?
Is it 'time' to go to the next Movement?
How much is 'Enough', 'Not Enough', 'Too Much' can be assessed. Much of this Judgment decision-making is done without having to think deliberately, but deliberation can consciously make those decisions.
Intro., Verse I, Chorus, Verse II, Chorus, and... what? Verse III? Or a Bridge to break the Repetition. Repetition supplies Structure the listener can relate to. They 'learn' the Composition as they listen. If it lacks 'Enough' Structure they may drift off to their own thoughts instead of pay attention, being entertained, engaged, in attentive listening. If it has 'Too Much' Change, instead of Repetition, that too may lose their attention. They come 'Unhooked' and we don't even know about 'The one that got away!'
The Songwriter's Judgment Call on Timing is strategic. Your Judgment may be that the minute-long Introductory Movement is fine may or may not be the listener's Judgment Call. The audience will be making its own 'Enough' Judgments.
We enjoy emoting, vocally, Lyrically telling our story, and our Judgment may differ from the listener's.
If sitting at a drum set and 'Composing', these attentions to Timing and Composition could help define that Structural 'base'.
I recommend this Compositional attention to Structure for rap.
A man came back from a tour of duty out of the country and asked, "When did rap become R&B (Rhythm & Blues)? Apparently the genre had changed perceptibly, to him, while he was away. I speculate that the 'industry decision-makers', perhaps the Composers themselves, perceived the Compositional benefits of mixing more R&B Structural Components into their works, to keep listeners Hooked. Rap can be very Repetitive, to the point of Monotony, which is 'relieved' by Change. The right Combination of Repetition and Change can keep the listener listening; Hooked.
Starting with the drum 'track' doesn't mean you're 'stuck' with it. If your guitar or keyboard work suggests Changes to what you've laid down to start with you can redo the percussion to pick up and support the new dynamics of the ongoing Composition. If your vocalization and Lyric suggest percussive Changes you can redo the drums. It's your Song, your Judgment call.
Keep going. You're on 'a' right track, maybe 'the' right track. Create. That, more than anything else, may be the strategic factor.