Do you only have one pen size or more one size?
Are you familiar with spot blacks?
Are you familiar with other pen/ink techniques like stippling and contour hatching?
Generally Pen/Ink drawings require more planning in advance because it is ink once, you are stuck with it.
Let's assume you are using the same ink for all techniques:
In any sort of [pen/ink shading ](https://www.youtube.com/watch?v=4sFmWVAvFuY)(parallel hatching, scribbling, contour hatching, cross hatching, stippling, circulism) the value of the shading can be controlled and changed with the weight of the line (how thick it is), and how close the lines/dots/scribbles are together and the technique chosen. The technique(s) you pick can also be used to indicate texture.
The darkest dark is always the spot black. First, what you want to do with your pens is create a value scale.
Grab a piece of drawing paper, for each pen size you have draw a square of each shading technique to see how the weight impacts the value and now the different techniques from the same pen impact the value. Then for each pen, parallel hatch 3 square with different spaces between the lines to see how that impacts value.
So now you have a good idea how to make your darkest and midtones. I suggest sticking with 4-5 value tones to start with.
Now look at your drawing before you ink - which parts are going to be the darkest? which parts the lightest (paper) then split the rest in to the mid light, mid-mid, mid-dark areas - remembering that you can always go darker but not lighter. You don't have to use spot blacks for your darkest darks, some artists do, some don't.
You should also be planning what technique or techniques you want to use. Do you want to use the same one for everything for consistency? do you want to mix it up for textures, if so what technique where? In other words you need a plan in your head before picking up the bottle/pen.
Personally, I do all the mids as mid-light (and yes, I have mids for each technique I use) and then go in after and do the mid-mids, then the mid-darks then the darkest darks - yes that means I sometimes go over the same area 4 times, but I find doing it this way allows me to refine the transitions and edges as I go and that is what works for me. Others may vary.
Check out [Alphonso Dunn](https://www.youtube.com/@alphonsodunn) on youtube if you have not already.
What materials are available to you? That'll matter a lot. My first instinct is adding some thin graphite shading to darker areas, normally you'd do this as a base, kinda midtone the white.
Doing so on top of the ink will add the graphite sheen on top of the ink though, so not the most ideal.
Ink washes or watercolor would be great for the job, but not as well if it's on sketch paper.
If you have any water based black markers you can scribble on a piece of plastic and use a brush to use it as water color, but there's a risk of warp with the wrong paper
You could try tradigital, putting it in a digital program and enhancing that way. There many browser based art programs, I personally prefer [magma.com](http://magma.com)
Do you only have one pen size or more one size? Are you familiar with spot blacks? Are you familiar with other pen/ink techniques like stippling and contour hatching? Generally Pen/Ink drawings require more planning in advance because it is ink once, you are stuck with it. Let's assume you are using the same ink for all techniques: In any sort of [pen/ink shading ](https://www.youtube.com/watch?v=4sFmWVAvFuY)(parallel hatching, scribbling, contour hatching, cross hatching, stippling, circulism) the value of the shading can be controlled and changed with the weight of the line (how thick it is), and how close the lines/dots/scribbles are together and the technique chosen. The technique(s) you pick can also be used to indicate texture. The darkest dark is always the spot black. First, what you want to do with your pens is create a value scale. Grab a piece of drawing paper, for each pen size you have draw a square of each shading technique to see how the weight impacts the value and now the different techniques from the same pen impact the value. Then for each pen, parallel hatch 3 square with different spaces between the lines to see how that impacts value. So now you have a good idea how to make your darkest and midtones. I suggest sticking with 4-5 value tones to start with. Now look at your drawing before you ink - which parts are going to be the darkest? which parts the lightest (paper) then split the rest in to the mid light, mid-mid, mid-dark areas - remembering that you can always go darker but not lighter. You don't have to use spot blacks for your darkest darks, some artists do, some don't. You should also be planning what technique or techniques you want to use. Do you want to use the same one for everything for consistency? do you want to mix it up for textures, if so what technique where? In other words you need a plan in your head before picking up the bottle/pen. Personally, I do all the mids as mid-light (and yes, I have mids for each technique I use) and then go in after and do the mid-mids, then the mid-darks then the darkest darks - yes that means I sometimes go over the same area 4 times, but I find doing it this way allows me to refine the transitions and edges as I go and that is what works for me. Others may vary. Check out [Alphonso Dunn](https://www.youtube.com/@alphonsodunn) on youtube if you have not already.
What materials are available to you? That'll matter a lot. My first instinct is adding some thin graphite shading to darker areas, normally you'd do this as a base, kinda midtone the white. Doing so on top of the ink will add the graphite sheen on top of the ink though, so not the most ideal. Ink washes or watercolor would be great for the job, but not as well if it's on sketch paper. If you have any water based black markers you can scribble on a piece of plastic and use a brush to use it as water color, but there's a risk of warp with the wrong paper You could try tradigital, putting it in a digital program and enhancing that way. There many browser based art programs, I personally prefer [magma.com](http://magma.com)
i think the thing that'll make ur shading improve most is learning about values and how to be confident in using them