Sigil:
This is the Seal of the Angel of Lost Things:
(The C-shaped part doesn’t need to be thicker than the other lines, that’s just how it came out when I drew it.)
What Name?
It’s best to use the full name/title the Angel of Lost Things to summon the Angel forth.
Using Greek, Hebrew, Latin, or other languages is possible, but the intention is to create an emotional resonance with the concept of “lost” within yourself – if English is not your first language, you may use the same words translated into your own natural tongue.
How To Work With The Angel Of Lost Things:
Call the name the Angel of Lost Things, using the Seal above.
If you wish to use candles, pink (especially), white, light blue, and gold are acceptable, if you wish to offer a food item, use candy, in pinks especially, and then consume it yourself after it has been left on the Seal or on an altar for the Angel for not less than 27 minutes, or 27 hours.
(As that suggests, 27 is a number of special significance to the Angel of Lost Things; this site gives the Ace of Wands as the Tarot card linked to 27, this page gives some gematria results for that number… among them, in Simple Gematria, is KEK. 
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Other: sweet non-alcoholic drinks (like strawberry milkshakes, or coconut water) are also acceptable, offered for an appropriate period of time and then received in the same way.
Pink cherry blossom is especially linked to the Angel of Lost Things, but it carries the current very strongly, so use with caution. After use, bury the cherry blossom in a garden or other open natural space, leave it on grass, or compost it - it must be returned to the circle of nature.
You can bless rose quartz and light blue calcite for this pupose for working with the Angel and also, as a dowsing tool for locating lost objects, but the simpler you keep things the better, so primarily, use the Seal and request the Angel help you to locate the lost item.
- The intention is to avoid losing yourself by creating conditions which, if not met, will make you feel as though you have failed.
And you can also use anything else pink, that’s nice , for want of a better description, like pink jewellery or pink tinsel! 
Background :
In spring of 2015 I visited a spirit I had previously discovered on the astral planes known as Dorr – you can read more about Dorr here.
I asked what the next stage was for me, in ascent and pursuit of various agendas, primarily theogenesis.
Dorr replied that I must choose which angel I would be – within my framework of understanding, angels are sentient upholders of reality in order that all being does not fall into insensate chaos (they sustain the canvas of reality, upon which lifeforms paint their own design).
They are also a harmonic of creation “closer” to Source than human consciousness.
So I chose the Angel of Lost Things, because this seemed closest to many of my interests and life themes.
The experience of becoming as the Angel of Lost Things was intense, like pouring large quantities of some kind of opaite directly into my brain – utter bliss and calm about the entire manifest reality, accompanied by a state of harmony with lost things (I got lost on streets I’ve known for years, was randomly approached by lost people, found lost objects, people in my life began having weird “coincindences” around the topic of lost items, and so on).
So it’s not exactly me, it was more that I was asked what angel I would be, if I was to be one, and that was the force I could most easily conceptualise being a pure current for, there was and probably always has been an Angel of Lost Things, but I share a link of some harmonic kind, and I seem able to become as the Angel at times, though it’s pretty debilitating.
I know how mad that sounds btw. 
Suggestions:
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Copy the Seal and sleep with it beneath your pillow, requesting a return of lost hope, lost enthusiasm, or lost abilities (including from past lives or bloodlines, note that this aligns with the March 1st workings of previous years) - you can attempt to use the Seal for lost loves but the Angel is unlikely to override someone else’s free will - but, give it a go if you’re feeling forlorn
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Travel to Dorr and ask what the next stage is for you, if you’re feeling stuck or between projects, or need creative inspiration of some kind
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Consider what your answer would be, if asked the same question (what would you be the Angel of?) - you may find it an interesting exercise in self-reflection, and understanding patterns in your life
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Last but not least, work with the Angel of Lost Things to locate lost objects, people, etc!
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