Magic is formulas, rituals, rites, and incantations. In order to cast a spell the wizard must be capable of speaking in their regular volume and moving their hands. This makes spell casting obvious, although some wizards learn illusions to conceal spell casting in general there is no doubt a wizard has cast a spell (a check vs wizardry plus intelligence, magic lore expert skill or 1/2 a hybrid wizardry skill plus intelligence vs the level of the spell will reveal what spell was cast. Education can be used but the difficulty is double).
There are two major types of enchanting. Simple enchanting requires time, ritual, and magic energy used temporarily. This is the type of enchanting that produces scrolls, potions, talismans, and amulets. The second type of enchanting binds part of the wizards soul into the object or area and causes them to permanently lose a portion of their magic energy pool. The binding process makes the powerful magic items such as enchanted swords, wondrous items, and staves.
Many minor items are created by a spell such as create magic scroll or talisman. These items are simply cast and then used as described. Other minor items are built or brewed using materials to make and infusing them with energy. A single use item such as a potion, arrow, or bullet is made with the energy of the spell desired plus an extra 50 and spells are limited to 8th level or lower. A spell carrier item has a spell bonded to it, but requires the use to provide the magic energy to fuel the spell; these items cost ten times as much energy as the spell costs to cast (A battery talisman or power stone may be included to power the effect). A mystic energy tap item is the same as a spell carrier but relies on being at a place of power where it draws energy to fuel the spell (these items will work continuously as long as the duration exceeds the time needed to activate the spell). An enchanted talisman can be made for 10 times the cost so that any caster may recharge it or for 20 times the cost it can be made to recharge itself at places of power.
Permanent spells and items that run continuously cost 1/10 the normal energy cost of the spell in permanent energy drain. If the desired effect is use based or instant the cost is for an item usable 3/day.
Spells and Sources
Palladium The spells from Palladium systems convert easily keeping the level and the cost in energy the same.
D20/Pathfinder D20 spells are the next most direct conversion; 0-9 range spells are double plus 1 so 0 becomes 1 (3 energy), 1 becomes 3 (10 energy), 2 becomes 5 (20 energy), 3 becomes 7 (40 energy), 4 becomes 9 (60 energy), 5 becomes 11 (100 energy), 6 becomes 13 (300 energy), 7 becomes 15 (600 energy), 8 becomes 17 (900 energy), and 9 becomes 19 (1500 energy); for 0-6 or less range double and add 2 so 0 is 2 (6 energy), 1 is 4 (15 energy), 2 is 6 (30 energy), 3 is 8 (50 energy), 4 is 10 (80 energy), 5 is 12 (200 energy), and 6 is 14 (450 energy).
Shadowrun Shadowrun spells are based on drain. base level is drain plus 2: L = 3, M = 5, S = 8, D = 12, add the force modifier to the drain level for effective level, so Detox light toxin becomes level 1 ([F/2-2]L) and Increase Cybered Attribute 4 becomes 15 ([F/2+3]D). Level then determines energy 1st = 3 energy, 2nd = 6 energy, 3rd = 10 energy, 4th = 15 energy, 5th = 20 energy, 6th = 30 energy, 7th = 40 energy, 8th = 50 energy, 9th = 60 energy, 10th = 80 energy, 11th = 100 energy, 12th = 200 energy, 13th = 300 energy, 14th = 450 energy, 15th = 600 energy, 16th = 750 energy, 17th = 900 energy, 18th = 1,200 energy, 19th = 1,500 energy, and 20th = 2,000 energy.
GURPS GURPS spells are based on energy, but most have a very small range, generally 1-3. To convert GURPS spells square the energy and if the spell has a variable energy assume 3 times the base (fireball is 1-3 so 9 Energy, explosive fireball is 2-6 so 36 energy). For level compare to the Shadowrun level vs cost chart and assign to the closest level.
This isn’t all encompassing, but gives a place to start.