If we knew how to get God?s attention and how to get a reaction from Him we would have much more confidence to pray!
He invites us to call on Him and promises to show us great and mighty things that we did not know.
Jeremiah 33:3
3 ?Call to Me, and I will answer you, and show you great and mighty things, which you do not know.?

NKJV
7121 qaraÕ { kaw-raw?}

a primitive root [rather identical with 7122 through the idea of accosting a person met]; TWOT – 2063; v (approach, confront, detain)

AV – call 528, cried 98, read 38, proclaim 36, named 7, guests 4, invited 3, gave 3, renowned 3, bidden 2, preach 2, misc 11; 735

1c) (Pual) to be called, be named, be called out, be chosen

7122 qaraÕ { kaw-raw?}

a primitive root, to encounter, whether accidentally or in a hostile manner; TWOT – 2064; v

AV – befall 5, come 4, chance 2, happened 2, met 2, fall out 1; 16

GK – 7925 { ar;q;
1b) (Niphal) to meet, meet unexpectedly
1c) (Hiphil) to cause to meet

The secret in calling on God in such a way to get his attention is to call until you have an actual encounter with the living God ? like Jacob with the angel. He said, ?I will not let you go until you bless me!? Sometimes we let go too easily.
When Jesus met the disciples on the way to Emmaus (?hot springs?) he made as if he was going to leave them. They insisted on him staying with them and eating with them. It seems as if God wants us to demand his attention. He wants to know how serious we are about having his presence with us, about hearing from him and speaking to him.

We have to accost the Lord: we need to confront to detain, to hold on until we have his full attention so that we are ensured of his response.

When God unexpectedly calls us by name he appoints, commissions and endows or empowers us to accomplish the task he has called us to do. So the same applies when we call unexpectedly on the Lord: we approach him and confront him with our request. That detains him and causes him to listen to what we have to say. As a result of our living encounter we literally give him the power of attorney to start acting on our behalf. We commission him as it were and appoint him to do the job for us.

33:3 The word ?mighty? could be rendered ?fenced in,? with the connotation being ?cut off? or ?inaccessible.? God is able to reveal that which has formerly been hidden, and He is committed to deliver and to preserve His people.

2. How this comfort must be obtained and fetched in?by prayer (v. 3): Call upon me, and I will answer them. The prophet, having received some intimations of this kind, must be humbly earnest with God for further discoveries of his kind intentions. He had prayed (ch. 32:16), but he must pray again. Note, Those that expect to receive comforts from God must continue instant in prayer. We must call upon him, and then he will answer us. Christ himself must ask, and it shall be given him, Ps. 2:8. I will show thee great and mighty things (give thee a clear and full prospect of them), hidden things, which, though in part discovered already, yet thou knowest not, thou canst not understand or give credit to. Or this may refer not only to the prediction of these things which Jeremiah, if he desire it, shall be favoured with, but to the performance of the things themselves which the people of God, encouraged by this prediction, must pray for. Note, Promises are given, not to supersede, but to quicken and encourage prayer. See Eze. 36:37.