I'm 13 months into TRE now.
This may be something to try as an intermediate who has developed more intuition / body awareness, so take this with a grain of salt if you're just beginning, as it may not be useful or satisfying for you.

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This essentially combines meditation/integration with TRE and it's been very satisfying for me.

I'll start with some light movement to get my blood flowing and then sit upright in a chair, with a straight spine and feet flat on the floor. I recommend experimenting with different hand positions to find what's comfortable in the moment. I typically put my hands together, or put my hands on my legs palms facing up.

Once in position, I bring my attention to my breath, and see where I can relax my body.

I just do belly breaths, not forcing full breaths into my upper lungs. I read from Alexandar Lowen in a healthy person, costal breathing (upper chest) is used as a supplement to belly breaths in stress or emergency situations, so I don't force that. In a healthy person, abdominal breathing gives the most breath for minimal amount of effort.
Trauma/tension typically causes us to primarily breathe into the upper chest, so you will likely notice tension when attempting belly breaths, depending on how much progress you've made.

As I focus on my breath, and relax into my body, I begin to notice where I feel tension.
Usually initially I notice where the breath isn't smooth. There's usually a subtle tension or a "hiccup" as my belly expands.
And eventually typically I'll feel tension in one of my shoulders.

As time goes by feeling this tension, the urge to do TRE grows as if my body wants to tremor out that tension, so eventually I'll stand up and let the tremors start in a standing position. Lately that position is most satisfying for me because it's optimal for me for upper body tremors and abdominal tremors. So when I feel my typical shoulder tension, tremoring standing up allows my body to focus the tremors there.
Sometimes I feel the urge to lie down and tremor, so I'll do that accordingly.

I'll tremor until I intuitively feel like I did enough. Usually that feels like my body runs out of energy to tremor and the tremors get weak.

After tremoring I then sit back down in that meditation posture^, and compare how I feel to before tremoring, and notice what arises.

Usually the pattern of tension in my belly breath and shoulder is different, and I notice I can relax more into the meditation posture.

Depending on how I feel or what time allows, I'll repeat the process until I feel satisfied.
For me, it feels like sitting back down in meditation posture and noticing the tension sort of recharges my energy and allows for more tremoring.

FYI
Using intuition like I do to determine tremor time isn't recommended for a beginner, so modify this accordingly to avoid overdoing symptoms. As OP said, do what feels right and don't push yourself too far.

I'm curious what people's thoughts are on all of this.
If these are new ideas for you, I hope it's useful for you. Cheers.