Frankincense and all blends of aromatic resins are burned by placing them directly on top of special charcoal burning in a censer or thurible.
The charcoal tablets should be handled very carefully, as follows:
1. open the air-tight roll; after taking the necessary tablets, put the remaining ones in the special resealable plastic bag (green and black grades)
2. take the charcoal tablet with the special pincers and place it in a vertical position; bring the flame close to the edge far from the pincers
3. it takes from 3 to 10 seconds for a first ignition (depending on the charcoal used but also on the kind of flame employed - candle, lighter - and on the humidity rate); after ignition has started remove the flame
4. ignition will be completed in 30 to 50 seconds; wait for the tablet to be totally incandescent before placing the charcoal tablet into the censer.
5. place the charcoal in a horizontal position with the concave part looking up; you can now put the frankincense or the resins on the charcoal; too much incense will suffocate the charcoal
6. never dipose of the ash remain in a waste paper bin; it might be still burning and there is a high fire risk.
In the lithurgy, a server called a thurifer approaches the person conducting the service with the thurible charged with burning tablets of red-hot charcoal. Grains of incense taken from their container (usually a "boat"), usually blessed with a prayer and spooned onto the charcoal. The thurible is then closed, and taken by the chain and swung by the priest, deacon or server or acolyte towards what or who is being incensed: the bread and wine offered for the Eucharist, the consecrated Eucharist itself, the Gospel during its proclamation (reading), the crucifix, the icons (in Eastern churches), the clergy, the congregation, the Paschal candle or the body of a deceased person during a funeral.
According to the Romal Missal:
276. Thurification or incensation is an expression of reverence and of prayer, as is signified in Sacred Scripture (cf. Psalm 140[141].2; Revelation 8.3).
Incense may be used optionally (ad libitum) in any form of Mass:
a) during the Entrance Procession;
b) at the beginning of Mass, to incense the cross and the altar;
c) at the procession before the Gospel and the proclamation of the Gospel itself;
d) after the bread and the chalice have been placed on the altar, to incense the offerings, the cross, and the altar, as well as the Priest and the people;
e) at the elevation of the host and the chalice after the Consecration.
277. The Priest, having put incense into the thurible, blesses it with the Sign of the Cross, without saying anything.
Before and after an incensation, a profound bow is made to the person or object that is incensed, except for the altar and the offerings for the Sacrifice of the Mass.
Three swings of the thurible are used to incense: the Most Blessed Sacrament, a relic of the Holy Cross and images of the Lord exposed for public veneration, the offerings for the Sacrifice of the Mass, the altar cross, the Book of Gospels, the paschal candle, the Priest, and the people.
Two swings of the thurible are used to incense relics and images of the Saints exposed for public veneration; this should be done, however, only at the beginning of the celebration, following the incensation of the altar.
The altar is incensed with single swings of the thurible in this way:
a) if the altar is freestanding with respect to the wall, the Priest incenses walking around it;
b) if the altar is not freestanding, the Priest incenses it while walking first to the right hand side, then to the left.
The cross, if situated on the altar or near it, is incensed by the Priest before the incenses the altar; otherwise, he incenses it when he passes in front of it.
The Priest incenses the offerings with three swings of the thurible or by making the Sign of the Cross over the offerings with the thurible before going on to incense the cross and the altar.