Once you have your smooth surface you can take care of any flaws that are left. Marks and cracks in the icing can be hidden by taking a small ball of icing, dipping it in some cornflour or icing sugar, and rubbing it over the problem area. The icing sugar will fill the crack and blend it into the surface, smoothing it out. Other marks such as cake smears or food colouring can often be removed by brushing on a little clear alcohol, such as vodka, and then rubbing lightly with some kitchen towel. Once the liqour has dried smooth out the surface again.
Once cooked, leave the cake to cool in the tin. When cool, remove from the tin and place on some baking parchment. Drizzle a couple of tablespoons of brandy (or your other chosen liquor) over the cake and wrap it up tightly in parchment and clingfilm or foil. Every few days unwrap the cake to feed it with another spoonful of liquor, then wrap it back up and return to a safe, temperate storage space.