How do I write transition sentences that don't sound forced?

[Olga]

My essays feel choppy. One paragraph ends, the next begins, and there's no bridge. A writing guide says transitions should “show the relationship between ideas” – contrast, addition, causation, sequence. They give examples like:

• “While X is true, Y offers a different perspective.”
• “Building on this idea, the next section explores…”

But when I try to write these, they sound stiff. My friend said to “read the end of one paragraph and the start of the next out loud. If they don't flow, add a sentence that connects them” . She also suggested “using the last sentence of a paragraph to introduce the next idea” rather than tacking on a transition at the beginning.

This makes sense but takes practice. For writers who've mastered transitions, what's your process? Do you write them as you go or add them during revision? I need a strategy that doesn't make my writing sound like a robot.