How to prevent top of dress bodice from curling forward

When I sew a girls dress with a woven cotton fabric sometimes the top of the lined bodice curls forward it does not stand up straight. It happened with a dress with a v notch at the top of the bodice. I cut down into the v of notch, trimmed the sides of the v then turned and press well after sewing. I am making a dress with a heart shape at the top of the bodice now and I'm concerned it may curl forward too. I will clip the curves. Does this happen only with v notches? Do you always trim the 1/2" seam down to 1/4" on the top of all bodices? I hesitate to use iron on interfacing because sometimes it ripples under the fabric. Thank you I appreciate your advice.