I've created plating solutions for Copper (from Copper Sulfate Pentahydrate) and for Nickel (from Nickel Sulfate Hexahydrate). For both, making the solutions was as simple as boiling water and mixing the chemicals until the solution was saturated. Once the solution had cooled, I filtered the solution through a coffee filter to remove any crystals and leave just a room temperature liquid.
For both making the solution and plating -- particularly for nickel -- many sources (complex solution recipe, nickel plating instructions) prescribe more complicated procedures. Adding acids to the solution or heating the solution while plating, but it hasn't been required. Making a simple solution and plating at room temperature (with low current on the order of 30 mA!) has been sufficient. With nickel and copper, whatever impurities or imperfections have been introduced by following this simple approach are too small for me to notice. Perhaps there's more resistance per square inch or it lacks a brighter luster.