Brit here. I think this is the most common tea-making process for Brits:

1. Use an electric kettle to boil some water (I think Americans often don’t have electric kettles, but nearly all Brits have them)
2. Get your teabag(s) (often 1 teabag per mug of tea) and either put them in a teapot, or put them straight into mugs, whichever you prefer
3. Pour the boiled water into the teapot or into the mugs to brew the tea
4. Poke the teabag(s) around with a spoon (I usually use the spoon to squeeze the teabag(s) against the side of the teapot/mug because it seems to make the tea stronger)
5. If you brewed the tea in a teapot, now is the time to pour it out into your mug(s)
6. Add milk to the tea in the mugs if desired (most Brits have milk in tea)
7. Add sugar to the tea in the mugs if desired (some people have no sugar, some have 1 or 2 teaspoons of sugar, some have more)
8. Enjoy your tea, but remember that it will initially be hot

Also you need to remove the teabag from each mug if you brewed the tea straight in the mug. I usually remove it before adding milk, but I think some people remove it after adding milk.

What kind of tea

I think the most common variety of tea in the UK is called English Breakfast. If you’re in another country and you find English Breakfast tea then that’s probably the most similar to standard British tea. Some Brits have other types of tea like Earl Grey, but that’s not as common.

condiments

See the steps about milk and sugar above.

what separates a good tea from a bad tea

I think most Brits like relatively strong tea, where the teabags have had a proper chance to brew. Some Brits might prefer weaker tea though.

whens a bad time to bring out tea versus a good one

I think a lot of Brits would say there’s never a bad time for tea.

You fuck with iced tea or is that a sin?

It’s not that common in the UK. You can buy bottles of iced tea in the average British supermarket, but it’s a bit of a niche drink.