When considering brushwork, the things you have to think about are:
-How does your brushstrokes describe the form? How are you describing different rates of turn of the form? Are you treating the slower turns the same way you’re treating the quicker turns? Are you using different brush types to produce different effects? For example, a flat sharp-edged brush for more distinct planes, and a soft-edged brush for gradations.
-If you are using brushes with distinct brush marks such as textures and bristle marks, are you using them effectively to convey different types of surface properties? For example, dirt, fabric weave, hair, skin pores, etc.
-Are you doing effective selective detailing, so the main focal points are eye-catching and the unimportant supporting elements are not competing with the focal points too much?
-Are you using different varieties of edge qualities such as from hard, firm, soft, to lost edges?
-Do you have painters you admire and try to learn from? Have you done master copies of their work to learn how they execute their brushwork? For example, many painters admire John Singer Sargent for his brilliant brushwork. Same with Richard Schmid. There are others like Anders Zorn, Gil Elvgren, Haddon Sundblom, Pino Daeni, Craig Mullins, Jaime Jones, Zhaoming Wu, and many more.