This is one of my favorite prayer to Loki.
O Son of Leafy Isle
and Ever-Biting Sky
I pray You hear this little prayer
Where ere You may reside
I pray You know Your Holy Name
Rests on lips of me and mine;
That always is there a place
When ere You come to dine
I pray You know that somewhere
Some will call You friend
That my children know Your deeds
And know where ere Youve been
I pray that You can see
The offerings left outside
That some carry love for You
A love we will not hide
I pray that You can hear
The songs that we sing
In praise of You, O Flaming Hair
In our small gatherings
I pray that You can feel, Loki
The love and trust and pride
For counting You among our Gods
In You, our prayers abide
Hail unto the Fiery One
To Hag and Aesir Bride
Hail unto Your Beloved Kin
Your family and Your lines
Hail to You Ever-Changing
To all Your blessings known
To Wyrd that You have made with us
To Wyrd that will be wove
My Ancestors have spoke Your Name
My heart knows but this:
My kith and kin are blessed by You
Because You do exist
Please hear this prayer I pray, Loki
Trickster, Fire, and Friend
We shall hail and praise Your Name
Beyond Yggdrasils End
Source:http://www.northernpaganism.org/shrines/loki/writings-for-loki/prayer-to-loki.html