I guess my question would be, why wouldn't you adapt whatever you might do indoors...? Was there something in particular you wanted that is different?
Indeed, I know of a great many cases where the services of most liturgical denominations have been done outdoors for various reasons. Anglican, Roman Catholic, Eastern and Oriental Orthodox, Methodist, indeed some Moravian and Eastern Orthodox services like the Sunrise service on Easter in the Moravian church and the Great Blessing of Water in the Orthodox church, always happen outdoors, as do many adult baptisms, most burial services except in the rare exception of internment in a mausoleum or the case of a columbarium located with indoor access, and a large number of marriages.
One thing I would advise is that a tent or umbrella be used to cover the celebrants, the altar and the Eucharist, and also at funerals after the burial occurs the cemetery will place a tent over the grave to allow the soil to stabilize. Tents are also advisable to provide shade in open areas and cover from the rain where it is not unlikely.
The Ethiopian Orthodox have lovely liturgical umbrellas used both inside and outside of their churches, which a young lady who was an Episcopal seminarian who I once met at my friend Fr. Dean’s parish before his retirement was thrilled by - she noted that they were in use at the fascinating if troubled St. Gregory of Nyssa Episcopal Church. I do have to say despite the criticism I have for that parish I admire the creativity, I simply feel like more discernment concerning non-Christian elements in their worship would have been desirable , for as it stands many Ethiopians and other Christians of various Eastern churches whose services have been used there have regarded it as culturally insensitive, So I would say if you are going to use Ethiopian liturgical umbrellas, you should do it at a service that is one that one could have found at most liturgical churches a century ago, so as to celebrate rather than appropriate their civilization’s exquisite heritage of liturgical arts. For example, the Ethiopian Orthodox Church officially prohibits the consumption of marijuana*, khat, and large amounts of alcohol, so using liturgical umbrellas at an outdoor wedding where at the same site a wedding reception with marijuana or people getting sloshed would likely cause offense.
*This came to the surprise of some Rastafarians who were persuaded to convert, but nonetheless a large number gave it up or struggled against it in order to be a part of the church of the martyred emperor, while others formed some strange groups like the “Independent Coptic Church” which blended Christian and Rastafarian ideas so that their “sacred herb” could continue to be smoked in massive quantities.
