Only one band should be visible after the second spin. If two bands are visible a third spin is necessary. Mark the volume level on the tube because isopropanol extracts water and it is necessary to replenish the water between each extraction to prevent the CsCl2 from precipitating. Isopropanol extracts the ethidium bromide and will be the top phase. Replenish the DNA volume to the mark with autoclaved water and repeat at least twice until all trace of red coloring is gone.
Ethidium bromide can inhibit restriction enzyme digestion.
If the yield is good a pellet will be visible after inverting several times to mix. If the yield is low i.e. no visible pellet place the tube at -20 degrees C for at least one hour then spin as above. It isn't necessary to respin unless the pellet is dislodged. Speed vac or air dry the pellets until all traces of EtOH have vanished. Run uncut and cut plasmid DNA side by side with standards on the gel to evaluate.