Using F-digivice, you can use different stuff to activade different digivolution lines. Here are main of them:

Crest (Partner digimon can digivolve to his Ultimate and Mega levels)
Required – Crest

Warp (By losing a lot of energy partner digimon digivolves straight to Mega level, passing Champion and Ultimate levels. However, if you have small Digivolving EXP rank, ypu won`t be able to digivolve this way)
Requires – Crest

Armour (Your partner digivolves to his Armour level, that is equall to Champion)
Requires – Digiegg

DNA (Two digimons can DNA-digivolve to one in order to become an Ultimate but it works only if you are a real friend with somebody)
Requires - friendship

Card (Actually it`s not a digivolution, by using cards you can modify your partner, giving him power, stamina – or two more paws)
Requires – Modify cards

Matrix (Use Blue card to make your partner digivolve to his Ultimate level)
Requires – Blue card

Biomerge (Combines digimon and his tamer into powerfull Mega)
Requires – Digivice, partner, tamer.

Spirit (Gives partner ability to digivolve to his Spirit level, Beast or Man)
Requires – Spirit

Elemental (Digimon digivove to his Champion or Ultimate level using an Element)
Requires – Element

Dark Crest (Digimon digivolves to his Dark Mega level, through he becomes practically uncontrollable)
Requires – Dark Crest

Werwolf ( Digimon digivolves to the exact same level, but in his dark side. For example, MetalGreymon will digivolve into ScullGreymon)
Requires – Werwolf activator

Ultimate (Immediately digivolves into his perfect form with all the energy and power. This is very rare ability for someone who won`t use digivices at all )
Requires – no digivice

Force (Digimon digivolves to his after next level, for example, from Rookie to Ultimate, with half of his strength)
Requires – Force activator

Chaos (allows a digimon to digivolve into his dark chaos mega form with all his power. Is plays only if his tamer is in extreme danger and the digimon is perfect in his Battle and Digivolving EXP)
Requires - unconscious tamer

HYPNOS (This gives ANY digimon ability to digivolve to any of his levels ONE TIME A DAY. Only HYPNOS members can use this digivolution)
Requires – Being a HYPNOS member

Ripper (Two digimons digivolve into one – same as DNA – but when battle is over the weaker one will be badly hurt)
Requires – Reaper tank

Integrate (combine three digimons together, releasing a Megadigimon, a Royal Knight or just extremely powerfull attack)
Requires – three real friends

Unite (combine ALL available digimons together in perfect war machine, through when they de-digivolve they`ll go to their digiegg forms)
Requires - no less than 1000 Digivolving points from everyone.

Core (Digimon digivolves using the Battle Cores he gained in battles. He can choose any of the form, from Armour to Unite, but he`ll loose soma battle cores after it)

Champion – 10 cores
Ultimate -25 cores
Mega -50 cores
Armour -15 cores

Requires – requested cores, elsewhere your digimon will de-digivolve to a digiegg and won`t digivolve to Fresh for 2 days.

Here are some Digital Force digivolutions of Digidestined.

Beast (Digidestined uses his force to become a digimon himself)

Soul (Digidestined combine their powers to digivolve to Alphamon)