I think the answer is that it depends what we are praying for.
We are told to give God no rest until Jerusalem is restored as a praise in the earth.
Isaiah 62:6 I have set watchmen upon thy walls, O Jerusalem, which shall never hold their peace day nor night: ye that make mention of the LORD, keep not silence, 7 And give him no rest, till he establish, and till he make Jerusalem a praise in the earth.
The ‘Lord’s prayer’ indicates a daily repetition in certain things
Matthew 6:9 After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name. 10 Thy kingdom come. Thy will be done in earth, as it is in heaven. 11 Give us this day our daily bread. 12 And forgive us our debts, as we forgive our debtors. 13 And lead us not into temptation, but deliver us from evil: For thine is the kingdom, and the power, and the glory, for ever. Amen.
Importunate prayer is held up as an example; exhorting us not to loose heart.
Luke 18:1-7 And he spake a parable unto them to this end, that men ought always to pray, and not to faint; 2 Saying, There was in a city a judge, which feared not God, neither regarded man: 3 And there was a widow in that city; and she came unto him, saying, Avenge me of mine adversary. 4 And he would not for a while: but afterward he said within himself, Though I fear not God, nor regard man; 5 Yet because this widow troubleth me, I will avenge her, lest by her continual coming she weary me. 6 And the Lord said, Hear what the unjust judge saith. 7 And shall not God avenge his own elect, which cry day and night unto him, though he bear long with them?
Jesus prayed three times that the cup might pass from him.
Matthew 26:39 And he went a little further, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me: nevertheless not as I will, but as thou wilt... 44 And he left them, and went away again, and prayed the third time, saying the same words.
Paul prayed three times about his thorn in the flesh before he got an answer.
2 Corinthians 12:8 For this thing I besought the Lord thrice, that it might depart from me.
Paul was in the habit of continually praying for others.
2 Thessalonians 1:11 Wherefore also we pray always for you, that our God would count you worthy of this calling, and fulfil all the good pleasure of his goodness, and the work of faith with power:
Philemon 1:4 I thank my God, making mention of thee always in my prayers,
He exhorts consistency in prayer
1 Timothy 2:1 I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men; 2 For kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty. 3 For this is good and acceptable in the sight of God our Saviour;
James 5:16 Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.
Luke 21:36 Watch ye therefore, and pray always, that ye may be accounted worthy to escape all these things that shall come to pass, and to stand before the Son of man.
We are to avoid praying for things to gratify our carnal desires.
James 4:3 Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts.
What we ask has to be in accordance with God’s will.
1 John 5:14 And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us: 15 And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him.
Faith in God plays an important part.
Hebrews 11:6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
James 1:5 If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. 6 But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed. 7 For let not that man think that he shall receive any thing of the Lord. 8 A double minded man is unstable in all his ways.
Paul learned an important lesson
Philippians 4:11 ...I have learned, in whatsoever state I am, therewith to be content.
The writer to the Hebrews gives this advice.
Hebrews 13:5 Let your conversation (way of life) be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee.
We don’t always know what we should pray for; but God knows what we need before we ask.
Romans 8:26 Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered.
We have to recognize that it may be God’s will not to give us what we ask for. Alternately the answer we seek may be a long time coming. How often we pray for something is a measure of how important it is to us
I hope you have found this helpful.