What tempering process do you use when moulding chocolates I want make moulded chocolate but am always having a hard time keeping the chocolate in temper for the sealing process.

I use the microwave method to temper the chocolate and I do so with a batch of about 600g. Once the chocolate is tempered, I fill the moulds with the chocolate and then empty the moulds back into the bowl of tempered chocolate. I find that when I do this the chocolate in the bowl is already setting and becoming hard.

One idea I had was to temper more chocolate so that there is more in the bowl and will keep in temper for longer. But if I do this, I will have a lot of tempered chocolate left over.

Is there a better or more efficient way to make a one-off batch of moulded chocolates?
Either use both methods or just use the second step to maintain the temper/work-ability of your chocolate:

A) Use the double boiler method to start tempering your chocolate.

A bowl/pan of chocolate sitting above a pot of hot water - the water should not touch the bottom of the bowl/pan.

B) Dip the bottom of your tempered chocolate in hot water for a few seconds, scraping the base (and sides) of the bowl/pan, mixing it into the rest of the chocolate.  
You can repeat this step if the chocolate is not warm enough/cools down.

Of course you could look at investing in a chocolate melter.