I don't know how to say sorry since it's not natural for me to apologize. so can you tell me a way on how to say sorry effectively?

i think the best way to apologize is giving gift and talk to the person with sincerity,

Yes, do it with sincerity.
Tell it clearly-state to the point
Let that person know that you're really sorry
Let go of your pride. :>

hope that helps you.

try to say sorry with sincerity... and try to fix those things or gap between both of you,..

I think you should just apologize.

Apology gifts add that 'extra
touch' to your apologies. Keep
in mind that they absolutely
aren't necessary for an
apology to be effective. What
makes them so special (and something to consider when
thinking about ways to say
sorry) is that they are NOT
necessary or expected. Just
make sure when giving a gift
that it is given WITH an apology and is not THE
apology itself. We've come across some
really interesting options for
apology gifts that show the
recipient that you went out
of your way to find
something special

say sorry and have sex after. that was very effective promise .....just apply it to your gf/bf .. ok? haha