Repeat if necessary. Its one drawback is that it is messy and stains, however if you wear protective clothing and ensure any spillage is wiped down immediately with a damp cloth you should have no problems. If results are still bad board is a failure and you must refer to Exposure and Developing tips for your next board. The tinning will greatly improve the solderability of the board. The tin will protect the copper from oxidisation.
Tin looks very thin - change solution.
Always use tungsten carbide drill bits. At approximately one third of the price MM reground tungsten carbide drill bits offer excellent savings.