Adding power to rolling stock

A cheap lighted caboose on the bay is a good source for pick-up rollers. Depending on the style of trucks you can remove just the rollers or change the trucks

Taking the thread topic name at face value,

1) If can't find the parts to convert/replace a particular truck style, run a 2-wire tether on a connector from an adjacent car that has power or for which you can get powered trucks (even if that car is not going to use the power itself).  Many prototype examples such as circus trains where a generator car provides power to many cars via tethered cables.

2) Battery power?  Some homework is required to match the power requirements to the battery "system" but with modern re-chargeable battery modules you can carry quite a bit of power in a small space.  For seasonal applications like a Halloween or Christmas train a single battery charge might even do the trick.  When you say "creative ideas" I figure you're not talking about interior lights that are always on!  As I see it, most "creative" animated cars don't run all the time anyway - one of those less is more situations.

3) And once you have power in the rolling stock, a related consideration is how you turn power on/off.  If an on/off toggle switch does the job, then great.  But "creative" suggests to me an animation that works "with" the layout...perhaps operating when it passes a particular point or in response to some external event.  These days wireless remote electronics can be installed for, say, $5 per car.  Note that for decades, one approach to bringing power into and controlling rolling stock was to install special trucks/power pickups and position said car over a special track section with 5 rails.

The 9050-150 shown HERE snaps in to almost every Lionel & K-Line plastic truck made since 1970 and can probably be adapted to many others as well.

For many Lionel and MTH trucks, the add-on roller kits are available.

Thanks for the info guys all of the rolling stock i have are metal trucks. The creative ideas ranged from basic lighting effects and detailed interior animations. The style of truck doesn’t bother me at all it’s more important for the addition of power. The battery ideal not so keen on seeing it would have to switched on and off . Track power is what I am looking for.

Thanks