Question about reward points.

You get points automatically all the time bit by bit.

Giveaways for games with only one * or no ** give you CV, which increases your level.

When creating a giveaway, check if the game has a tiny red star like this (after the name of the game): *
1 star means the game has reduced value, so it has probably been in a bundle.
If the game has two red stars it means it will not contribute toward your giveaway level progress. The game was probably given away for free at one point.
If no stars you will probably get the most value out of it unless you got it from a bundle that just started.

Or the way the FAQ puts it:
No Value:
No contributor value when given away after the effective date.

Reduced Value
15% contributor value when given away after the effective date.

Full Value
100% contributor value when given away.

More information here: https://www.steamgifts.com/about/faq
I hope this cleared it up some. I remember there may be website that calculated exactly what you would get but I'm not sure if it's still around.
EDIT: if anyone sees I said something incorrect please correct me, I have not used steamgifts much in the last few months :)

Tks a lot. This is the info im looking for :)

ESGST browser addon helps on this as it tells you expected points.
Im not big on add-ons and dont allow auto running scripts. Yet I find myself enabling it about 75% of the time I visit SG.

Also if you're looking at gifting games thru Steam rather than sending a Steam key,
https://www.sgtools.info/deals

Just be careful and pre-check the giveaway for the regions that are more than 12% of your currency rate to avoid not being able to gift.
https://steamdb.info/app/892970/
Even then its not foolproof.

Too combat the additional layer of publishers blocking any gifting to another region, I have acquired alot of Friends from Steamgift that I nickname them with their country. That way I do a pre-emptive dry run to make sure I can send to the more expensive EU (Im US).
Works so far for me the last 6 months. Hopefully I havent jinxed it.

I up to helping fellow apes out on checking gifting to more expensive regions to see if it passes my experience.