For the macaron's shell:
3/4 cup almond meal (almond flour)
1 cup confectioner sugar
2 egg whites
1/4 cup granulated sugar
Optional: rose extract and red or pink gel paste food coloring

In a separate bowl, beat the egg whites until frothy then add the sugar. Beat until you reach a meringue like consistency. When you get soft peaks, add some food coloring, note that color tends to fade down when baking. Then beat again until you get stiff peaks.
Add to your meringue about half of your dry mixture (almond meal and confectioner sugar), fold it carefully until fully blended then add the rest and fold again. (if you made chocolate mousse, the folding process is the same).
Then transfer your batter into a piping bag with a round tip. I personally use a ziploc bac and I cut a corner off. On a baking sheet lined with parchment paper, pipe carefully small round circles. You decide what size you want, though keep them apart from each other about an inch.
Once you are done with piping them. Tap your sheet 2-3 times as to get air out (so no bubbles) then let sit 15-30 min to dry.
Once they are dry, place them in the middle rack of your oven at 300 degree Fahrenheit and bake them for 12-15 min. Don't forget to turn your baking sheet mid process. I tend to turn mines at 5-6 min. They should rise and form feet.

Let them cool off completely before filling them. They are very fragile while warm.
For the filling:
1/2 stick of butter softened (unsalted)
1 cup of powdered/confectioner sugar
1-3 Tbsp of heavy cream
rose extract to your taste
Optional: food coloring
In a bowl, beat your butter until soft and creamy. Add gradually your sugar and mix until all blended. Add your rose extract (I like a strong floral flavor so I add quite a bit). Add the heavy cream, it will make the consistency of your buttercream much smoother and spreadable. Add some food coloring if you wish. (I add 1 drop to get a very pale pink to contrast with my darker pink shells). Transfer to a piping bag and fill your macarons.
I strongly suggest storing your macarons in your fridge until serving. I try to let them sit for a day as to get the flavor to really sit.
Another favorite flavor of mine is rose-raspberry.
I use the same shells, though I add a bit of rose extract in my shell batter. I use Bonne Maman raspberry jam as my filling. Voilà Rose-raspberry macarons.
Note: the rose buttercream above tends to be too sugary to my taste though all my friends like it as is. I personally cut back a bit. Hence, some people use 1 1/4 cup confectioner sugar, I tend to cut it to 3/4 cup for 1 cup of almond meal. Though it is entirely up to you.