This article has a lot of information about using leaves to help your garden. The section “Options for Managing and Using Leaves” is especially what you’re looking for.

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Leaf Management – Soil Improvement
Leaves may be collected and worked directly into garden and flower bed soils. A 6 to 8 inch layer of leaves tilled into a heavy, clay soil will improve aeration and drainage. The same amount tilled into a light, sandy soil, will improve water and nutrient holding capacity.
A recommended strategy for using leaves to improve soil in vegetable gardens and annual planting beds is to collect and work them into the soil during the fall. This allows sufficient time for the leaves to decompose prior to spring planting. Adding a little fertilizer to the soil after working in the leaves will hasten their decomposition.

When you are planting in the spring,

“For vegetable gardens, a thick layer of leaves placed between the rows function as a mulch and an all-weather walkway that will allow you to work in your garden during wet periods.”

https://aggie-horticulture.tamu.edu/earthkind/landscape/leaf-management-plan/.