Play Chapter 7 and hack the weapons terminal toward the end before entering the final turret section. Choose "No Shield Regen" while hacking to get +300% experience points and slot the x6 XP Multiplier, several times if possible. Once done, go to the Jazz prison area, clear out the basic enemies, go to the objective marker, and jump on the turret. Once the enemies spawn, use the T.E.C.H. XP bonuses and destroy all approaching enemy. Use each bonus as the previous one lifts. Either wait for Jazz to die or select the "Restart from last checkpoint" option before the end of this section to farm experience points. You will keep all earned experience points after restarting and can repeat the process as many times as desired.
Play the "Lost Vault" in Chapter 2 and get to the "Search for the Leaders of the Insecticons" objective. Switch to Starscream and clear out the waves of Insecticon enemies. When the room is empty, use the weapon terminal and leave it behind for an autosave to keep the experience points earned. Choose the "Restart from last checkpoint" and repeat the battle as many times as desired.
The following T.E.C.H. Assists are useful for the corresponding situations:
Battle Drone with Cybertronian Ultimate Repair Energy Drone
The Battle Drone will steadily attack enemies within range, which is useful when you need cover fire or need to know where enemies are located. C.U.R.E.D. will heal a nearby ally. You can only have one of the drones active at a time.
Because the barrier does not move, it is not going protect you from enemies on the move. It is most useful when you need to replenish your shield without cover.
Energon Heal Burst
Useful when in a support role. It immediately heals allies and also allows them to heal over time.
Energon Recharger with Shield Restore Booster
This combination allows you to regenerate health very quickly while having the ability to immediately restore your shield as soon as the Energon Recharger effect wears off.
Guided Cluster Grenades
Places heat-seeking mines that is effective when used near a group of enemies.
Provices better armor and increases your damage while in vehicle mode. It is more beneficial for aerial vehicles.