I would say: Just talk to them really.
They are Our relatives (so to say) in Christ and should be treated and approached in such matter as well.
Im impressed With Your attitude towards praying to the Saints as you havent even begun RCIA yet

it makes me so happy to hear about Your passion for the Catholic faith.
I have to admit that I myself havent gotten used to pray to Saints yet.
I have prayed to them in the past (mostly St Joseph and Mary Magdalene), but it didnt feel Natural for me to do so.
Hopefully I`ll get used to it at some point or another as they play a (name removed by moderator)ortant role in many catholics lifes.
Do you pray to Mama Mary?
I think she is the best Place to start if you dont already pray to her a lot that is

And She answers, trust me
The Holy Rosary are a tremendous gift given by Our heaventhly mother.
it is the most powerfull prayer in the entire chruch except from mass.
As for closing Your prayer.
I usually just say Amen or though him Christ Our Lord.
Its really up to yourself
When it comes to prayers to Mama Mary I usually Close my prayers With a few Words of veneration, such as "you dearest Queen who allways walk With me and guide me on Your Sons Our Lords paths, in you I trust my faithful, loving and tender Mama Mary. Please hear and answer my prayer oh sweetest Mom. Amen.
Create Your own prayers, they are the most genuine and heartfelt prayers anyway

As for praying to the Saints it may be smart in the beginning to mention Jesus often during Your prayers to avoid worshiping the Saint Your praying to (trust me it may happen be axcident). It worked well for me at least (but as I said I dont pray alot to the Saints anyway). As a former Lutheran I struggled a lot With it in the beginning.
I hope you found something helpful somewhere along all my rant.
May God be With you on Your Journey of faith.
RCIA is so challenging and exciting, look forward to it
Yours in Jesus and Mary