Aeros are usually visual manuevers, so as long as you are making intentional spin entries and recoveries, you should be looking outside. The direction of a turn during spin is usually quite easy to figure out, especially if you are doing it intentionally, since you will almost always give aircraft pro-spin rudder when it stalls, to give it enough yaw to develop a spin - if you'll push left rudder to develop a spin, then push right rudder to get out of it. It depends on the type, but many spin-certified CS23 aircraft require rudder input to actually hold the aircraft spinning - if you release it, the rotation will slowly decelerate, all you have to do is give it a bit contra-rudder and pull it out of a dive. Recovery from dive is where you should glance an airspeed indicator to see how much buffer do you have from Vne (again, it depends on the aircraft) - nevertheless, don't be too agressive on the stick during recovery: controls are very effective at high speeds and a bit of overreaction could dynamically stall the aircraft.
Of course, if an aircraft gets into spin in IMC conditions, then looking at your turn coordinator should show the direction of a spin, but in VMC - look outside
