Well the only time you would really have to enter GST in the gen journal is for correcting errors if an alteration to GST is required or if there is a GST clearing balance when doing a commencing entry. The other uses of the general journal, correct me if I'm wrong will never have GST attached: Bad debts, contribution of NCA by owner, withdrawels of stock.
For a correcting entry I always write down what was meant to be entered and what has been entered. Then you can easily see what corrections you need to make, if the GST entry is incorrect then you would include this in your entry (like your example regarding electricity and wages).
For a commencing entry well that is pretty easy. It will tell you in the list of accounts if GST clearing is a CR or DR balance. You simply CR or DR this figure in the gen journal with all the other commencing entries.
I.e.: Jane contributed the following on the 1st of Jan to commence the double entry recording system:
Stock $50 000
Debtors $25 000
Loan - ABC Finance $10 000
GST Clearing $5000 DR
Gen Journal Entries:
Stock Control DR 50 000
Debtors Control DR 25 000
GST Clearing DR 5000
Loan - ABC Finance CR 10 000
Capital - Jane CR 70 000
Hope this helps, MBA