Through the day I often just say "Help me" to Him, and speak to Him a few times over the course of a normal day, at least in short phrases like "Help" and the random, "Thank-You".
Anything longer is not practical for me 'in the trenches', so I keep is as simple as possible.
Before "Modeh Ani", I ask Him to "please help me be Yours today."
The longer versions of prayers are nicer for me when I have time, like during or after a meal, or a mincha or ma'ariv, etc.
I like seeing meaning in a posuk and schlepping it with me through at least a part of the day.
What Chaza"l wrote for us in the nusach of tefilah expresses our deepest needs and desires, though we might not be aware of it.
And our own begging and speaking to Hashem reflects what we are aware we need, here in the darkness of the golus inside our bodies.
We are yidden. We have always done both.
(See the Me'iri on the sugya of t'fillas haderech in b'rachos. He explains that the tefillos haderech and suchh that chaza"l composed were just springboards for every yid to make up his own words and express his present needs to Hashem in an open and honest way.)