Well, the easiest thing to wear in hot summer months might be a dress. You'd choose styles depending on whether you're short-waisted (streamlined empire-waisted styles would look good provided the neckline is not too high, or, with your longer legs, you could try the current drop-waisted styles too) or long-waisted (try a peplum style?), and a wrap dress suits most shapes and sizes. Straight sheath styles usually look great on strong shoulders too.
If you prefer skirts, your longer legs and shoulder width will let you wear midis with ease, I think. Longer walking shorts and tapered cropped pants that end just above the calf should work too. With your IT shape, you should be able to carry off more voluminous styles like slouchy pants too.
Keep your tops unfussy at the shoulder and neckline, and avoid puffy sleeves or gathers at the shoulders. Raglans often work very well on strong shoulders. If you like to emphasize your shoulders, military detailing near the shoulder or yoke like epaulettes might be interesting in jackets. Avoid garments that swing too dramatically away from the shoulder, as in your case it might mean an overwhelming amount of fabric. Look instead for tops that fit through the bust and then flare, if you like a looser silhouette. Structured, tailored shirts can be harder to fit on an IT, so look for those with princess seaming or darts or gathers under the bust; OR choose a soft fabric that drapes well (silks and chiffons typically do).
I'm sure the other ladies will chime in with more ideas. Meanwhile, it would really help if you can tell us a little about what you normally wear or would like to wear.
