Make it a cultural value to avoid shortcuts, technical and design alike, while in the grind of shipping product. Done right, this can flip the internal pressure from taking shortcuts to avoiding them.
When the above isn’t practical, or even desirable, prioritize eliminating the design shortcuts with structural or system-wide impact that are harder to unwind down the road. This involves tight collaboration between designers and engineers to make a joint assessment. “Easy” design fixes can end up involving far more engineering work than meets the eye and vice versa. Be careful to not paint yourself into a corner with product decisions that make incorrect assumptions about what’s easy vs. hard to fix down the line.
When your product does accrue UX debt, make sure to have a backstop that prevents it from piling up past the point of no return. Keep a running list of UX debt items and make sure it’s visible to the product team. Then create dedicated time and space for the team to pay down debt. This could be a fixed allocation of debt tasks every sprint, a dedicated debt sprint every few sprints, or whatever arrangement works best, as long as it’s explicit and sufficient.