Prayer could mean different things to different people depending on your level of consciousness.
It is a very personal affair between you and God.

Most times people pray to either "Ask for something" or say "Thank you" or "Glorify" the Lord.

 

Glorification

nivrtta-tarsair upagiyamanad
bhavausadhac chrotra-mano-'bhiramat
ka uttamasloka-gunanuvadat
puman virajyeta vina pasughnat

Glorification of the Supreme Personality of Godhead is performed in the parampara system; that is, it is conveyed from spiritual master to disciple. Such glorification is relished by those no longer interested in the false, temporary glorification of this cosmic manifestation. Descriptions of the Lord are the right medicine for the conditioned soul undergoing repeated birth and death. Therefore, who will cease hearing such glorification of the Lord except a butcher or one who is killing his own self?

 

The Sweetness of the Name

From the life of Srila Rupa Gosvami

One day, Rupa Gosvami was busy writing Vidagdha-madhava Mahaprabhu arrived unexpectedly and was impressed by his beautiful handwriting, comparing it to a string of pearls. He read the verse that Rupa had just finished composing, which was a glorification of the Holy Name:

'I do not know out of how much nectar the two syllables of Krishna's name have been composed; dancing madly on my tongue, they awaken in me the desire to possess many mouths. As they sprout in my ears, they give me the hope that I may one day have millions of ears, and as they enter into the garden of my heart they overcome the activities of every one of my senses, leaving me inert!'

Hari Dasa Thakura, the acharya of the Holy Name, was amazed to hear such an extraordinary glorification of Krishna's name and he started to dance. He said, 'I have heard the glories of the Holy Name from many scriptures and sadhus, but never have I heard a description like this of the sweetness of the Holy Name.'

 

Chanting

The best prayer is to chant the maha- mantra

Hare Krishna Hare Krishna
Krishna Krishna Hare Hare
Hare Rama Hare Rama
Rama Rama Hare Hare

It is the most powerful prayer to go within and connect you with God (Krishna). In that state of alignment only he knows what is best for you.

Once you realise that your only reason for birth is to serve God then thereafter every time you chant these syllables, you are actually asking God to give you the opportunity to serve him. Hence your chanting becomes your constant prayer.

The opportunities to serve him may come in the form of difficulties, pain, sorrow, laughter, joy, abundance etc.

Once you realise that "this too shall pass" and every opportunity is just a fleeting moment to take you to the next level of consciousness you will be able to accept every pain or laughter as an act of God to take you closer to him. This is a powerful realisation once you have got it. Please be aware there is a difference between just knowing and actually having a realisation.

On pilgrimage /tour our advice to you is to just chant. Do not worry about your personal prayer, a particular person or situation that you forgot to mention. Krishna can see and knows all.