I have a kinda new Chingling.

He's at Level 17, and the rest of my team is about 20-23.

I've been keeping him at the head of my party, and training with him, because it started at Level 13, just last night.

So, any tips on how to get it really happy so it will evolve, possibly tonight or within the week?

give it massages that will make it happy, I think there are berries that make it more friendly to. Make sure it doesn't die when you go into a battle.

Soothe Bell works too. Keep it as Chingling's item.
And yeah, the EV-reducing berries increase happiness.

Where can I get a Soothe Bell in Diamond?

As komms said, not letting it faint is a big thing x_x I don't remember how much it takes down the happiness level, but I think it's quite a bit.

Soothebell can be found in the Mansion below route 212..a maid should give it to ya!

Route 212 is by which city again? [/fail at pokemon]

And it hasn't fainted yet! If it gets close, I pull it out or heal it with a potion.

Some things that will help are:
1.) Getting the soothe bell like they said
2.) getting a massage in Veilstone city or at the Ribbon Club in the resort area
3.)Try not to let it Faint, but if it does it's not the end of the world since it only goes down 1
4.) Leveling up makes it go up a lot
5.) using the EV reducing berry's help the most at a whopping +10
and route 212 is south of Hearthome city from what I remember
Hope i helped ^^

Most importantly keep it in your party 24/7, one trick would be don't send it out to battle but go to the spa and massage lady and also just give it exp share, that'll increase its happiness coz it doesn't get poisoned or faint then.

If the made any sense that's what I always do for these kind of evolutions

Don't give Chingling any Medical Powders (like Energy Roots or Heal Powders) or trade Chingling. It'll reset the happiness meter. Also, leveling up and vitamins (like Calcium) boosts happiness.

EDIT: Also, Chingling evolves at night.

Is there any way for me to check what level happiness he's at?

you have that friendship app on your poketech don't you? Or is it on platnium only >< idk any if the hearts are 2 big ones than he has good friendship with you

on platinum the friendhship poketch app hold the stylus on the pokemon wait for 2 big hearts to appear after 3 small ones.
platinum too go to the footsprint man on the beach east of pastoria..

in hg/ss talk to your poke here and there to check their happiness and stuff...

In Hearthome, there's an NPC character who rates happiness in the Fan Club.

I think giving it stat increasing items such as Protien and Calcium helps.

Paradox wrote:Also, leveling up and vitamins (like Calcium) boosts happiness.

Yep.

And yeah, there's a happiness app on the poketch for DPPt, I dunno which number it is though.