This is a tricky question to answer only because everyone seems to have their own idea of what the ideal tunic length is. For the record, I prefer tunics that end right where my butt check meets my leg (read here for more). Any shorter than that and I can’t wear the top with leggings. Any longer than that and it begins to swerve into dress territory. 

Here are a few options I found for you:

1. Old Navy Tami Tank, $8 - I’ve found Old Navy tanks (and some tops) to generally be quite long. 
2. Daydreamer LA Long-Sleeved Top, $34 
3. Vero Moda Oversize Tunic, $27.59 - ASOS also carries a good selection of oversize tees/tunics. 
4. Old Navy Turtleneck Tunic, $19.94
5. Alloy Poison Ivy Oversized Tunic, $19.90-$21 
6. Daydreamer LA Oversized Tee, $29
7. Victoria’s Secret Oversized Scoopneck Tee, $26.50

Other tips:

• I’ve found the best oversized tops and tunic-like basics at H&M. They’re typically very inexpensive ($6-$20) and are usually available in most neutral colors (gray, black white).  
• Loungewear specialty lines or stores like Aerie, Gap Fit or Victoria’s Secret’s PINK line also carry tunic-length tops. 

I hope this helps! Good luck on your tunic hunt. 

There is nothing worse than a pair of transparent leggings! I’ve had personal experience with a few of the above pairs, but included a couple others that I’ve heard good things about too.

1. LOFT Slim Leggings, $24.50 - I don’t own these myself, but have heard that they are nice and opaque. 
2. Aerie Slim Gym Skinny Pant, $19.99 - Technically these are gym pants, but they’re cut like leggings. These are some of my favorite yoga/gym pants and the wide waistband helps with the pesky legging muffin top problem.
3. Anthropologie Classic Leggings, $28 - Another pair that I hear is good.
4. Target Long Leggings, $8 - I’ve actually had great luck with some of Target’s leggings. You have to be more choosy since they can be thinner, but I have a few pairs that have held up well. 
5. Gap Pure Body Leggings, $29.95 - The best thing about Gap Body is the quality for the price. I don’t own any lululemon, but I have a few friends who say Gap Body is comparable. 

A few tips:

• Leggings made by hosiery/undergarment specialty companies are generally not a great idea. Spanx leggings, for example, look like thick tights. You can see the transparency in this photo.
• Synthetic materials will give you a more opaque finish, but the trade-off is that they’re sometimes shiny and that can also look weird. A thick cotton blend has worked best for me. 
• Fleece-lined leggings can help make the material less see-through. (And they’re also so warm for winter commuting.) Urban Outfitters, Plush and Victoria’s Secret all make them.