At last—decent rain over a wide area. Now the trick is to keep an effective eye on what happens next on the parasite front.
As a starting point do a Worm Egg Count (WEC) on a couple of mobs about 8 weeks after the rain ceased. The exception is where you got something useful out of the last lot of rain. In that case do your WEC in around 4–6 weeks after the last fall to see if things are on the rise.
If the rain has been followed by hot (over 30°C) dry conditions, it is unlikely there will be much action until there is more significant rain.
If, as we all hope, there is a lot more rain spread out until the end of March, then monitor more at 6–8 weekly intervals, maybe more often on young sheep.
Use the WormBoss Drench Decision Guide. It makes life simple and it works: http://www.wormboss.com.au/tests-tools/drench-decision-guide/sheep/pastoral.php
Blowflies are unlikely to be much of an issue for a while. In the event the rain continues into February/March, then you will need to make sure the jetting races and gear are in working order.